DOE/NASA/501 94-38

NASA TM- 86873

8 __4_0

Baseline Performance and EmissionsData for a Single-Cylinder, Direct-Injected, Diesel Engine

Robert A. Dezelick, John J. McFadden,

Lloyd W. Ream, and Richard F. Barrows

National Aeronautics and Space AdministrationLewis Research Center

September 1984

Prepared for

U.S. DEPARTMENT OF ENERGY

Conservation and Renewable EnergyOffice of Vehicle and Engine R&D

DISCLAIMER

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ERRATA

NASA Technical Memorandum 83638DOE/NASA/50194-38

BASELINE PERFORMANCE AND EMISSIONS DATA FOR A SINGLE-CYLINDER,

DIRECT-INJECTED, DIESEL ENGINE

Robert A. Dezellck, John J. McFadden,

Lloyd W. Ream, and Richard F. Barrows

September 1984

Cover, title page, and report documentation page: The Technical Memorandumnumber should be TM-86873.

Figure 21: In part (a), the Duration label should read Duration, 22°; inpart (b), Duration, 25°; in part (c), Duration, 30°; and in part (d),

Duration, 34°. Also, in figure 21(c), 232 g/kW-hr BSFC should appear in

the lower right corner. In the figure 21 legend, the fuel quantity should

be 140 mm3/cycle.

Figures 37 to 41: In the legends, delete inlet air temperature, 34 to 37 °C;add inlet air pressure, 262 kPa.

Figures 42 to 45: The key should read Inlet air pressure, kPa. The ordinate

scale label for the second graph from the bottom should read CO emission,

percent.

Figure 56: Key symbols (top to bottom) should be _, [-7, _. The top valueon the ordinate scale should be -.05.

DOE/NASA/50194-38NASA TM- 86873

Baseline Performance and EmissionsData for a Single-Cylinder, Direct-Injected, Diesel Engine

Robert A. Dezelick, John J. McFadden,

Lloyd W. Ream, and Richard F. BarrowsNational Aeronautics and Space AdministrationLewis Research Center

September 1984

Work performed forU.S. DEPARTMENT OF ENERGY

Conservation and Renewable EnergyOffice of Vehicle and Engine R&DWashington, D.C. 20585Under Interagency Agreement DE-AI01-80CS50194

BASELINE PERFORMANCE AND EMISSIONS

DATA FOR A SINGLE CYLINDER, DIRECT

IN_ECTED, DIESEL ENGINE

Robert A Dezelick, John J. McFadden,Lloyd W. Ream, and Richard F. Barrows

National Aeronautics and Space AdministrationLewis Research Center

Cleveland, Ohio 44135

SUM_MARY

The Department of Energy (DOE), Division of Transportation Energy Conservation, hasestablished several broad programs aimed at reducing highway fuel consumption. Within

the Heat Engine Highway Vehicle Systems Program is a subproiect that addresses control

technology for the reduction of particulate and gaseous emissions of diesel engines.

Program management for this proiect has been delegated to the National Aeronautics andSpace Administration (NASA), Lewis Research Center.

The research engine tested was a 120-mm- bore by 120-ram-stroke, single-cylinder

open- chamber, four-stroke-cycle, diesel engine with a 17.29 compression ratio. A

modular engine instrumentation system (MEIS), developed at NASA Lewis, was used to

provide a real time computation of the indicated mean effective pressure developed from

the pressure-volume diagram. Baseline performance data were developed and compared

with data supplied by the manufacturer, inlet air pressure and temperature effects were

evaluated, and exhaust emissions data were collected under various operating conditions.

Baseline exhaust emissions data were developed for CO, HC, NO x, total particulatemass, the soluble organic fraction of the total particulates, and exhaust smoke opacity.

Emissions of CO increased with speed due to lower volumetric efficiency at higher speeds.

Hydrocarbon emissions and total brake specific particulate matter were proportional to

engine speed for constant fuel iniected quantities and inversely proportional to load.

Oxides of nitrogen values decreased with an increase in engine speed from 2500 to 3000

rpm for constant fuel quantities, and decreased between 1500 and 3000 rpm for higher

fuel quantities (120 to 140 mm3/cycle).

The inlet air pressure and temperature to the engine were changed to simulate the

effects of supercharging and turbocharging. Optimum engine performance, based on

specific fuel consumption and mean effective pressure, was obtained with an inlet air

pressure of 329 kPa. Lowest exhaust emissions and smoke opacity were obtained with

inlet air pressures of 372 kPa or higher. The inlet air temperature effects at 2000 rpm

indicate that mean effective pressure improvements on the order of 8 to 13 percent can

be obtained with 37.8 ° C inlet air temperature compared with 107 ° C. This improvement

is indicative of the benefit to be derived from aftercooler/intercooler control techniqueson turbocharged engines.

A mathematical relationship was developed to predict total measured particulate

matter as a logarithmic function of exhaust smoke opacity plus total exhaust hydro-carbons. The calculated particulate emissions were used to assess the effect of inlet air

pressure on particulate formation.

The MEIS independently assesses real-time mean effective pressures for the upper loopof the pressure-volume diagram, the lower pumping loop, and the sum of the two loops.Real-time values of actual FMEP are shown to be 19 to 29 percent higher for the engine

under load (at fuel quantities of 60 to 140 mm3/cycle, respectively) than for a motoredengine at rated speed (3000 rpm). However, motored friction, in the normal sense,

includes both pumping and fricion mean effective pressure. Real-time values by thisdefinition were also assessed under different operating conditions. The results of this

analysisindicate that FMEP + PM£P for an engine under load (140 mm3/cycle), at rated

speed (3000 rpm), isabout the same as the motored engine value, but as much as 15

percent lower'than the motored engine value at 1500 rpm. Itwas determined that positive

work can be accomplished from the pumping loop by increasing the inletair pressure,by

decreasing the exhaust backpressure, or by a combination of both methods. For one

example, a 13 percent gain in performance was obtained by increasingthe inletair pres-sure from 262 to 414 kPa and by reducing the exhaust backpressure from 207 to 124 kPa.

INTRODUCTION

The Department of Energy (DOE), Division of Transportation Energy Conservation, hasestablishedseveral broad programs aimed at reducing highway fuel consumption. One

such program isthe Heat Engine Highway Vehicle Systems Program. Within that program

is a subprolect which addresses control technology for the reduction of particulateand

other emissions from dieselengines.

One of the NASA programs underway at Lewis isdirected toward reducing fuelconsumption and exhaust emissions for lightweightdieselaircraftengines for generalaviationuse. One accomplishment of thisprogram has been the construction and

development uf a fullyinstrumented, slngle-cylinder,dleselengine test facility.Because

of the slmUarlty in oblectlves between advanced automotive and aircraftdieselenginetechnology, itwas technlcally feasibleand cost effective to combine selected NASA

research effortswith those of the Department of Energy (DOE).

The data and technology developed in thisproject are intended to provide the basic

emissions and performance technologies that willhelp DOE to independently assess the

environmental acceptability of the open-chamber dieselengine for general highway

operation and to show the potentialvalue for tested control concepts in future regulatorydecisions.

This control technology part of the program encompasses the testingand evaluation ofa slngle-cylinder,open-chamber, diesel,test engine. Tests were conducted with the

obiectlve of accumulating repeatable baseline data and assessingthe effects of various

input variableson engine performance and exhaust emissions. A secondary oblectlve wasto explore the capabilityand accuracy of differentinstruments as measurement

technique s.

The single-cylinderresearch engine (SCRE) test facilityat Lewis, was put into an

operational status,and baseline performance data were collected and compared with data

provided by the engine manufacturer. Inletair pressure and temperature were varied to

demonstrate the best combination of these variables for minimum specificfuel consump-

tion,exhaust emissions, and particulates. A mathematical expression was developed to

predict the effect of engine operating parameters on the formation of totalparticulates.

A Modular Engine Instrumentation System (MEIS), developed at Lewis, for real-timemeasurements of mean effective pressure,was modified to provide independent assess-

ment of the power loop (upper) and the pumping loop (lower) on the single-cylinder four-

stroke cycle engine. This provided the capability to independently assess friction and

pumping losses under loaded engine conditions and to more accurately evaluate the effects

of such control strategies as turbocharging. Friction and/or pumping losses under loaded

engine conditions were also compared with similar data developed by the more

conventional motoring procedure.

APPARATUS AND PROCEDURE

Test Facility

The single-cylinder diesel engine test stand installation is shown in figure 1. The engine

is coupled to a 22-kW motoring and a 93-kW absorbing dynamometer. Engine cooling is

controlled by a closed-loop water system with an engine driven pump. On the cooling loop

is a heat exchanger that uses cooling tower water. Fuel is supplied to the engine from a

gravity-feed float-controlled tank, to an in-line, fuel injection pump. Fuel is supplied to

the gravity tank from an outdoor source consisting of a 0.189-rn 3 (50-gal) drum with an

appropriate filtering, pumping, and measuring system.

Inlet aim system. - The inlet air system uses surge tanks to dampen flow pulses and

provides air from a 690-kPa plant source. Conditioning systems provide for air pressures

from ambient to 690-kPa and temperatures from ambient to 121 °C, with specific

humidities from approximately 0.09 g H20/g dry air to saturation.

Exhaust system. - The exhaust system incorporates a remotely controlled valve that is

used to control the engine backpressure and to simulate the effects of a turbocharger.

For a majority of the tests conducted, the backpressure was held at 80 percent of the

inlet pressure. Surge tanks are used in the exhaust system to reduce the pulses from thesingle- cylinder engine.

Engine Description

Engine data. - The following table describes the single-cylinder test engine.

Bore, mm (in.) .................................... 120 (4.724)

Stroke ........................................ 720 (4.724)

Percent first-order balancin_ .............................. I00

Piston displacement, cm3 (ino) ............................ 1357 i82.8)Number of piston rings ..................................... 4

Clearance volumes, cm 3

Combustion cavity in the piston ............................... 63.2

Valve pockets in cylinder head

Intake .......................................... 2.3

Exhaust ......................................... 2.0

Quartz transducer cavity ................................. 0.4

Injection nozzle cavity ................................. 0.5Piston to head clearance ................................ 14.92

Total clearance volume ................................... 83.32

Compression ratio: (1357 + 83.32)/83.32 ........................... ]7.29

Four valve cylinder head: 2-intake, 2-exhaust and 2-camshaftsCylinder head thickness gasket, mm .................. ............ 1.6

Rocker arm ratio ...................................... I:l.5

Valve lash, ] mm

Intake ........................................... 0.4

Exhaust ........................................... 0.6

Approximate lift, ..................................... 9.7

Fuel injection line:

Outside diameter, mm .................................... 6

Inside diameter, mm _ ?ooo*oeelole,.,..ololwoiio.,.le,.I.°, L.

Length, mm ......................................... 600

Nozzle holder opening pressure, MPa (psi) ...................... 25.5 (3700)

Nozzle

Number of holes ....................................... 5

Hole diameter, mm ..................................... O.3G

Length to diameter ratio, L/D ............................... 2.8

Sac volume, mm3 ..................................... 3.6

Spray angle, deg ...................................... 150

Nozzle valve and seat diameters, mm ........................... 6 by 3.5

Fuel injection equipment. - The injection pump has a four-cylinder case. Elements 3and 4 are blank, and 1 and 2 are parallel and working.

The two injection pumps used the same cam profile (fig. 2): One has two 10-mm-

diameter plungers, with delivery valve retraction volumes of 120 mm3; the other has3

9-mm-dlameter plungers, with delivery valve retraction volumes of 70 mm .

In)ectlon timing was controlled by a motor driven timing device, where one revolution

of the timing device corresponds to a variation in Injection timing of 1° of engine crank

angle. The total in)ection timing range available is approximately 20 ° of crankshaftrotation.

Lubricating oil system_. - The lubricating oil system has a capacity of 14 liters(14.8 qt) and contains an englne-driven oll pump. Oil temperature control is provided.

Exhaust Analysis System

Emissions samplinA system. - The engine exhaust gas sampling system has provision [or

exhaust gas analysis and particulate measurement. For exhaust gas analysis, a continuous

sample is drawn from the pressurized section of the exhaust line. The gas flows throughsample lines (maintained at 190 ° C) to the gas analysis instruments. Particulate and

gaseous emissions were measured for single modes of operation according to the EPAFederal Test Procedure (FTP), Heavy Duty Engines, Code of Federal Regulations (CFR),

Title 40, Part 86, Subpart D, Section 86.345-79.

A schematic of the sampling transfer and data handling system is shown in

Figure 3(a). When not sampling, the sample llne is purged using air. The sampletemperature is maintained within allowable llmits in the transfer system in order to

maintain the sample's integrity.

The exhaust gas analysis instrument facility flow diagram is shown in figure 3(b). Thesystem is capable of measuring the concentrations of carbon monoxide (CO), carbon

dioxide (CO2), nitric oxide (NO), total oxides of nitrogen (NO), total hydrocarbons (HC),xand oxygen (O2). Table l(a) lists information for the exhaust gas analysis instruments used.

4

Chart recorders are provided on the gasanalysis instrument panel as well as panel

analog meters. The recorders are used to monitor stability when changing from one testcondition to another.

Calibration. - Zero and span gas calibrations are traceable to the National Bureau ofStandards. The calibration system consists of 16 high--pressure gas cylinders fitted with

pressure-reducing regulators. The gas cylinders are enclosed in a cabinet provided with a

hood and an induced draft fan. The fan discharge is ducted through the outside wall,

providing dilution and removal of any leakage gas during calibration. The calibration

gases are fed to a calibration gas panel located behind the gas analysis instruments in the

control room. Stainless-steel tubing is used between the cylinders and the calibration

panel. The panel is setup to provide a known calibrated gas for each instrument. Flexible

Teflon lines are used between the calibration panel and the instruments. The zero gas

used for measurement of NO/NOx, CO, CO 2 and 0 2 is nitrogen. Plant air is passed

through a catalytic device, which then provides the HC-free air used as the zero gas forthe measurement of total HC. The flow schematic for the exhaust gas analysis system isshown in figure 5.

Sixteen span gas cylinders provide a range of known concentrations so that calibrationcan be accomplished at various operating conditions. Table II shows the concentrations of

the span gas bottles available for use in the test cell.

Particulate sampling system. - The equipment for particulate sampling consists of a

dilution tunnel, sample probes, filter cassette sampling system, vacuum pump, sample

flowmeter, and a control unit. A schematic of the dilution tunnel and equipment is shown

in figure 4. The 25.d-cm-dlameter and 305-cm-long tunnel provides for complete mixing

of the dilution air and exhaust gas before sampling. The dilution air enters the tunnel

from the test ceil, passing through an impregnated filter for removal of hydrocarbons.

After sampling, the air and exhaust pass through a heater to a positive displacement

blower, and, finaUy, exhaust through the roof of the test ceil. The purpose of the heater

is to maintain the inlet conditions to the blower. The blower speed may be varied and is

used to control the amount of air diluting the exhaust. Tunnel flow is adjusted to keep the

sampling temperature below 52 ° C (125 ° F). An air dilution flow of eight times the

exhaust flow is normally enough to keep the temperature below 52 ° C (125 ° F).

There are two probes at the end of the 305-cm section to pick up the exhaust. The

dilute gas passes through either the partlculate filter cassette or through a bypass filter.

An automatic flow controUer maintains an established flow rate through the probe andfilter. The specifications and operating guidelines are presented in table Ill.

The sampling filters were conditioned in a humidity chamber for 24 hr before

weighing and particulate collection. After collection, the filters were again stored in a

humidity chamber to stabilize mass to the original humidity before weighing. Total

particulate mass from each test was determined by adding the particulate mass from both

the primary and backup filters. A representative number of filters were placed in glass

Soxhlet microextractors, and the soluble organic fraction (SOF) was extracted using

dichloromethane solvent. The samples were then reconditioned in the humidity chamber

and reweighed. The difference in mass between the total particulate matter (TPM) and

the soluble organic material (SOM) represents the unextractable residue, or solid massfraction (ref. 1).

The microbalance used for this measurement is accurate to ÷0.01 mg. The net weightof the TPM, the sample probe flow volume that passed through tl_e fllter, and the sample

5

time are recorded manually and entered into the data collectorsystem for processing.The soluble organic and solidmass fractionsare also manually recorded.

Instrumentation

The engine test operators console and engine instrumentation panel are shown infigure 5. Some of the instruments used are as follows:

(I)In-llnelightextinction meter for measuring smoke opacity.

(2)Filtersampling smoke meter.

(3)Blow-by meter, used to monitor the conditionof the engine and measure

crankcase gases vented to the atmosphere.

(4)Linear, differential,inductive type valve lifttransducer,used to determine theposition of the valves (inletand exhaust).

(5) Linear, differential,inductive type needle llfttransducer, used to monitor the

position of the valve in the nozzle.

(6)Piezoelectric,water cooled, transducer, used to measure cylinder gas pressure(24.8 MPa max.).

(?)Temperature controlled,mirrored, photoelectric sensor,used to obtain dew point.

(8)A modular engine instrument system (MEIS) (ref.2),used to provide the following:

(a) Pressure-volume diagram of the thermodynamic cycle, on an oscilloscopedisplay, which is updated every cycle. The modular unit displays indicated meaneffective pressure (IMEP). Associated modules display peak cylinder pressure, inengineering units, which are updated each cycle, and the degrees before or aftertop dead center (TDC) where peak pressure occurs. These data are transmitted

to the data acquisitionsystem.

(b)Another unit provides the log function of cylinder pressure and volume on an

oscilloscopedisplay. A Polaroid picture,or the displayitself,may be measured

with a protractor. The tangent of the angle then provides an on-llne value of the

polytroplc exponent for any portion of the pressure volume diagram.

(c)Another module displaysthe peak injectionpressure and the angle before topdead center (BTDC) where the peak pressure occurs.

(d)Also availableas a module isa unit that willaccept four parameters such as

cylinder pressure, injectionpressure,IMEP, etc. This unit willsample and store

up to 200 cycles and displaysthe mean and standard deviation values. The fourparameters can be shown on an oscilloscopeas a seriesof vertical bars (one percycle).

The major measured parameters are listedin table IV. In general, the overallaccuracy of each individualdata point is0.5 percent of the fullscale value of thetransducer.

All instrumentation is connected to a data system known as ESCORT which provides

a wide variety of computerized data services to the research facillties at Lewis. A

remote acquisition microprocessor (RAMP), located in the test facility, serves as aninterface between the facilities instrumentation and monitoring devices. A minicomputer

performs online calculations and outputs engineering unit displays on cathode ray tubes

(CRT's) in the test facility.

Selected portions of the data can be recorded by a signal to the minicomputer. This

then passes the data to a collector system which records the data on magnetic tape (legal

record tape) and passes the data to the main computer for final processing. Hard copy

data can be printed out at the test facility from any of a number of CRT displays that

have been previously programmed. The time, date, and a precision digital barometer

attached to the data collector are read onto the tape before adata record. The ESCORT

system also provides digital signal conditioning. The facility is placed in a null position

and zero data are taken. Calibration resistors are automatically switched in, and the span

data are taken. The correction factor for each channel is then calculated, stored, and

recorded on the data collector for use in the central data-reduction system. These values

are checked each test day against a baseline set of values for drift exceeding 2 percent.

Calculations

Calculations in this report are based on standard-day conditions of i00 kPa and

15 ° C. The water correction factor, calculated air to fuel ratio, etc., calculations were

developed for use in CFR, Title 40, Part 87, Subpart E; exhaust emissions (new and in use

aircraft piston engines). These, in general, agree with Title 40, Part 86, Subpart D,

Section 86.345-79 emission calculations for heavy duty diesel engines.

Test Procedure

Before starting a test, all instruments were calibrated. Pressure transducers were

automatlcally calibrated by the ESCORT data system. The data system was brought on

line, and the test cell brought to the null condition_ that is, no flow, with the pressure

transducers at atmospheric pressure. By communicating with the minicomputer via a

typewriter and push buttons, zeros were recorded in the data system, and the instrument

spans were recorded (resistance calibrations). The data system was then returned to the

data mode and digital readouts were updated. The engine was then started and brought to

operating temperature. For this series of tests, the engine water temperature was held at

77.8 ° C (172 ° F) and the engine oiltemperature at 91.1 ° C (196 ° F). A test point was then

established by setting the desired air inlet pressure and temperature and the proper

exhaust pressure. Data points were taken at speeds of 1000 to 3000 rpm in increments of

500 rpm. A dynamometer load was then set to establish equal increments of fuel Glow per

cycle from 40 to 200 mm3/cycle, w.'.th 35 percent smoke opacity being the normal cutoff

point. Injection timing was then adjusted to the desired setting (normally to maximum

power), with the limits being a maximum IMEP of 2.5 MPa at 2000 rpm, or a maximum

IMEP of 2.0 MPa at 3000 rpm.

When all values are stabilized, including emission data, a data point was taken. Five

scans of data were taken for all parameters with approximately 1 sec between scans.

When the data collector has transmitted the data from the data tape to the computer, theoperator was notified by a typed slgnal which gives the exact time of transmittal and the

run number. Computer printouts of the data were received the next day, and gave anaverage (for the five scans), minimum, and maximum values, in both milllvolts and

engineering units, for all the data channels. The printouts also tabulated results of engine

flows, emissions, engine performance, and heat balances. Data were saved whenrequested for plotting of various parameters.

TEST RESULTS

Acceptance Testing

The curves shown in figure 6 are the initial test results for the single-cyllnder testengine in the Lewis facility compared with the engine manufacturer's data. The differ-

ence in values is attributable to the variations in fuel specifications, piping arrangements,transducer sensor locations, etc. The volumetric efficiency curves (fig. 7) demonstratethe effects of inlet manifold resonance which occurred at 2000 rpm. This appears to be adeslrable feature for this engine when operated at this speed, but the inlet manifold wasmodified (enlarged) so that other effects would not be masked.

Data derived from the various test runs of the engine facility are used in many ways.The primary purpose is to establish good, repeatable basellne data so that the effects ofair, fuel, or hardware changes to the engine can be recognized from the data. A secondpurpose is to establish or verify the accuracy of various instruments or measurement

techniques being proposed or investigated. The third purpose is to provide researchinvestigators with the data necessary to compare the theoretical with the actual values,while visually observing how changes affect or limit theoretical goals. Many of the curvesprovided are for the use in follow-on investigations and provide the background orbaseline data required to show trends.

Inlet Pressure Effects

The inlet air pressure of the engine was changed while maintaining the exhaust pres-sure at a 1.25 inlet to exhaust pressure ratio PI/PE. This value was used throughout theprogram to simuiate a typical turbocharger unless stated otherwise. Fuel in}ection timingwas set for maximum BIVLEP. Figure 8 shows that the air-to-fuel equivalence ratio ((A/Factual)/(A/F stoichiometrlc) decreased with increased load at any fixed inlet pressure.

_igures 9 to 12 show the various performance parameters as they are affected bychanges in inlet air pressure. It can be observed that optimum engine performance (brakemean effective pressure (BMEP), brake power output (BPO), brake specific fuel consump-tion (BSFC), and brake thermal efficiency) occurs with approximately a 329 kPa inlet airpressure, while maintaining the pressure ratio at 1.25, and inlet air temperature at27+5 ° C. As shown in figure 9, increases in inlet air pressure from 329 to 414 kPa do notsignificantly affect engine BMEP for any of the fuel quantities shown. Figure 10 showsthat brake power increased 30 percent by raising the inlet air pressure from 193 to 329

kPa for 140 mm3/cycle. Figures 11 and 12 show that the lowest BSFC and highest brake

thermal efficiency values occur at an inlet air pressure of 329 kPa. Figure 13 shows theeffect of speed on peak cylinder gas pressures with increasing load at different inlet airpressures. Injection timing was adlusted to maintain maximum cylinder pressure withinrecommended design limits.

Figure 14 shows peak cylinder gas temperature plotted against BMEP for differentfuel quantities and five inlet air pressures at 2000 rpm. A computer equilibrium sub-

routine for hydrocarbon fuels was used to calculate the peak cylinder temperature, or thetotal equilibrium combustion product temperature (TECPT). Peak cylinder gas tempera-tures decrease with increased inlet air pressure for constant fuel quantities as shown for2000 rpm operation. Figure I5 shows the effect of speed on peak cylinder gas tempera-

ture at different loads for each of five levels of inlet air pressure. Figure 16 showssimilar effects of inlet air pressure on exhaust gas temperature for different speeds andloads.

Figure 17 shows how increased A/F's affect BMEP for different fuel quantities andengine speeds. Optimum performance (maximum BMEP) occurs at A/F's greater than 30.

Figure 18 shows BSFC plotted against A/F for different inlet air pressures.Optimum BSFC occurred at A/F's > 30. Best overall fuel consumption at both speeds wasobtained with an inlet air pressure of 329 kPa. Figure 19 shows the same effect in termsof brake thermal efficiency at 2000 rpm. Figure 20(a) shows that the sensitivity of peak

cylinder pressure for inlet air pressures of 329 kPa and greater, required retarded timingat the higher loads (A/F < 405 in order not to exceed the maximum design limit. Figure20(b) shows peak cylinder temperature as an inverse function of A/F and proportional toload or fuel quantity.

Fuel Injection Timing Effects

The data obtained from the photographs of the oscilloscope traces (fig. 215 demonstrated the increase in the duration of injection as a function of speed, ranging from 22 °

at 1500 rpmto 34 ° at 3000 rpm for 140 mm3/cycle. The average duration was 2.1 msec,

and the average needle lift rise time was 0.4 msec. From interpretation of the pressurediagrams (fig. 25) and from the camshaft analysis (fig. 35, it can be shown that (bycalculations5 over 90 percent of the fuel is injected by expansion of the fuel after thepoint of peak injection pressure. This behavior is similar to that of an accumulator fuelinjection system. The result is a decreasing rate of injection that is neither congruentwith nor controlled by the pump camshaft profile.

The oscillograms of figure 21 also illustrate how the peak cylinder gas pressure was

kept below allowable limits by ad)usting the timing, with respect to speed _hile maintaining the best BSFC. The dynamic effects of the injection system were exemplified byinjection pressure increases with increases in engine speed; that is, 41.6 MPa at 1500 rpmto 65.7 MPa at 3000 rpm. For these curves static timing merely refers to a referencepoint for the start of plunger lift in the injection pump. The approximate relationship of

static timing with the open position of the nozzle valve is shown in figure 22. This openposition of the nozzle valve occurred at the approximate point in the cycle where peakiniection pressure occurs and is the reference used in this report for dynamic injectiontiming.

Figure 23 shows the injection and ignition delay variables for five fuel quantities andfour speeds with optimum injection timing. Figures 24 and 25 show the effect of injectiontiming on part load performance (BMEP and BSFC, respectively5 at three speeds.

Inlet Temperature Effects

Volumetric efficiency can be a misleading parameter when evaluating superchargedengines. By definition, volumetric efficiency is the ratio of the actual weight of airinducted by the engine on the intake stroke to the theoretical weight of air that shouldhave been inducted by filling the piston displacement volume with air at atmospherictemperature (ref. 35. Volumetric efficiency, by this definition, can be a useful reference.However, with supercharged engines, the denominator becomes a variable determined byactual inlet manifold conditions. The ratios might suggest that volumetric efficiency

increaseswith increased manifold temperature. This is a mathematical anomaly since theinlet air mass charge is less with higher inlet air temperatures (fig. 26).

For parametric analyses, BMEP and BSFC are more meaningful indicators of overallengine performance. Improvements in BMEP on the order of B to 13 percent were

obtained with reductions in inlet air temperature at 2000 rpm (fig. 2?). Slightly lessimprovement is shown for 2500 rpm. Figure 28 shows improvements in BSFC for the sameconditions. These sets of curves are indicative of the benefits to be derived from

aftercooler/intercooler control techniques on turbocharged engines. In general, optimumtn)ection timing is not influenced by changing the inlet air temperature for lowest BSFCvalues.,

Exhaust Emissions - Baseline Results

Table V summarizes the mean values for baseline exhaust emissions with in}ectiontiming set for optimum engine performance (minimum BSFC and maximum BMEP). Inletair pressure was set for 252 kPa and inlet air temperature for 34 ° C. Figures 29 to 32show baseline brake specific CO, HC, NO , and total particulate emissions plotted against

xBMEP, engine speed, and A/F. The CO emissions increase with speed at the higher loadsbecause of lower volumetric efficienctes. Lowest CO values occur with fuel quantities of

100 mm3/cycle in the range of 35 to 48 A/F. As shown in figure 30, HC emissions

decrease with increasing load, or lower A/F, but tend to increase with speed for mostfuel quantities. The brake specific oxides of nitrogen (BSNOX) emissions (fig. 31)decrease with increased speed between 2500 and 3000 rpm for fuel quantities between 60

and 140 mm3/cycle. For higher fuel quantities of 120 and 140 mm3/cycle, there is also a

general decrease in BSNOX emissions between 1500 and 3000 rpm. As shown in figure 32,total measured brake specific particulate matter (BSPM) decrease with increas- ing loadbetween 1500 and 3000 rpm. This reduction in totaI measured particulates direc- tionallyfollows the same trend shown for hydrocarbons with increasing load.

In-line optical smoke extinction meters were used to determine exhaust smokeopacity and to calculate total particulate matter as determined by the method developedand described in references 4 and 5. The exhaust volumetric flow rate was corrected for

temperature at the smokemeter to determine actual volumetric flow rates. CalculatedBSPM was determined from

where

BSPM =(Cm)(EXVOL)(IO -3)

kW

-122 ln(1-10-_) mg/m 3Cm= L

and where

LN

EXVOL

mean wave length of lens of smoke meter (0.146 m)opacity, percent

exhaust volumetric flow rate, m3/hr

Calculated BSPM for four engine speeds and five loads are compared with measuredBSPM in figure 33. The data are scattered and no correlative trends are apparent. Thetotal particulate mass, however, comprises complex mixtures of solid and liquid com-pounds. The solid fraction is primarily carbonaceous matter, and the liquid fraction is

10

mostly organics and sulfates. As postulated by Greeves (ref. 6), total particulate masscontains the black soot formed in the high-temperature fuel-rich regions of the diffusion

phase of burning and that fraction of the total HC mass emission which condenses at the

particulate sampling filter. Total particulate then becomes mostly a function of bothsmoke and HC emissions. Calculated BSPM is shown in figure 34 plotted against smoke

opacity. A least squares linear regression was performed to produce the following rela-

tionship between calculated BSPM, considered as the solid fraction of total particulates,

and smoke opacity:

BSPMcalc = 0.08(percent opacity) + 0.06

With this highly boosted engine (262 kPa inlet air pressure), many of the smoke

opacity readings are extremely low, less than 5 percent, which is the threshold of

visibility. Consequently, the correlation is not exact, but the trend is apparent that smoke

opacity and calculated BSPM are more functions of the solid fraction of total particulates

than of total particulates. The soluble organic mass fraction (SOF) is shown in figure 35

plotted against brake specific hydrocarbon emissions. The calculated SOF shown for this

plot was determined by subtracting the calculated BSPM (a logarithmic function of smoke

opacity) from the measured total particulate matter. This plot produced the following

relationship between the calculated SOF and BSHC:

SOFcalc = 0.80 BSHC - 0.83

These two calculated expressions can be combined to produce the following:

BSPM - BSPM _ SOFmeas calc calc

= 0.08 (percent opacity + 10 BSHC) - 0.77

The results of these combined expressions show better agreement when totalmeasured particulates are compared with particulates calculated as a function of both

exhaust smoke opacity and exhaust hydrocarbons (fig. 36). Test points include four enginespeeds and five loads at each speed.

Exhaust emissions - inlet air temperature effects with variable timing

Figures 37 to 41 show the effect of inlet air temperature on fuel consumption,

BSNOX, brake specific hydrocarbon (BSHC), and brake specificcarbon monoxide (BSCO),

for five fuel quantities at 2500 rpm. The effects of three iniectiou timings are sho_nt for

2500-rpm engine speed and 262-kPa inlet air pressure. The lowest inlet air temperature

generally produced the lowest BSNOX, BSCO, and BSFC. Retarded in}ection timing

showed more consistent trends in reduction of BSNOX than for other gaseous emissions,

but with significant penalties in BSFC.

Exhaust Emissions - Inlet Air Pressure Effects

Figures 42 to 45 show the effect of inlet air pressure on smoke opacity and gaseous

emission concentrations at four speeds. The lowest level of emissions and smoke opacity

generally occurs with inlet air pressures at or greater than 372 kPa, while maintaining aninlet to exhaust pressure ratio of 1.25. Injection timing was set for optimum performance,

that is, lowest BSFC and highest BMEP for each speed. Total measured particulate data

were not collected for this series of tests. Figure 46 was constructed on the basis of

11

calculated brake specific particulates(BSPM) to establishthe effect of increased inletair

pressure on particulates. Calculated BSPM ispostulated to be a function of exhaust

smoke opacity (solidfraction)and BSHC (solubleorganic fraction),as previouslydescribedand shown in figure36. Figure 46 shows that particulatesare a function of A/F as

influenced by inletair pressure and that totalparticulatescan be held to a minimum for

A/F's greater than about 35 at 3000 rpm, 40 at 2500 rpm, 45 at 2000 rpm, and 50 at 1500rpm. Particulates tend to increase below these A/F thresholds and demonstrate the

potential for supercharging techniques to control particulates.

Exhaust Rmissions - let A Fuel

Several tests were conducted with Jet A fueland compared wlth the dieselcontroltest fuel (DF-2). Fuel characteristicsfor both are shown in table V. The cetane value for

this particularbatch of Jet A fuel isessentiallythe same as DF-2 (4?.3and 47.8,respec-

tively). The cetane value for Jet A, however, isnot normally controlled at the refineryand can have a wider range of values. Aromatics and oleflns,however, are about 50

percent lower for Jet A. Comparative emissions characterization resultsfor both fuels

are shown in figure 4? for 2000 and 2500 rpm. Tests were conducted at three fuelsettings,3

100, 120, and 140 mm per cycle. The same injectiontiming was used for both fuels,andno attempt was made to optimize In)ectiontiming for Jet A fuel. At both 2000 and 2500

rpm lower peak cylinder gas pressure and lower BSNOX resulted with Jet A fuel,but

higher BSHC emissions resulted. At 2500 rpm BSFC, BSCO, and particulatemass emis-

sions were lower with Jet A fuel. But at 2000 rpm the values were lower with DF-2 fuel.

FrictionMean Effective Pressure/Power

Motored frictionisnormally used as a convenient way to calculate IMEP by addingthe motored frictionmean effective pressure (MEP) to the measured brake MEP, as

determined from the dynamometer output. Motored frictionMEP, which includes the

pumping loop MEP for four-stroke cycle engines, does not account for actual firingpressures and temperatures, thermodynamic environment, and gas flow dynamics. The

importance of these considerationsismore apparent with supercharged and turbocharged

engines. Now, with the convenience of sophisticatedelectronic chips and microproces-

sors,various schemes are availablefor real-time displaysof engine parameters. TheLewis developed MEIS (ref.2)provides a real-tlme computation of the total indicated

mean effective pressure (IMEP t)from the pressure-volume diagram. Itisthe sum of the

compression-expansion and intake-exhaust loop MEP's. The MEIS was modified to

provide, independently, the IMEP value of the compression-expansion loop (upper loop ofu

the diagram), the PMEP value of the intake-exhaust or pumping loop (lower loop of the

diagram), and the sum of the upper loop + the lower loop of the pressure-volume diagram

(IMEPt). Actual FMEP values under loaded engine conditions can now be assessed on a

real-time basis on four-stroke-cycle engines to provide more accurate engine results.The FMEP isequal to (IMEP + PMEP) - BMEP. The IMEP isshown in figure48 to be a

U U

constant value across the engine speed range with the engine under load for each of threefuelquantities,while maintaining a constant inletair pressure of 260 kPa and a constant

exhaust backpressure of 210 kPa. The sum 12dEP ÷ PMEP for the same set of condi-u

tions shows the negative influence of pumping work, or pumping mean effective pressure,with increased speed. Values of IIV[EP + PMEP greater than the IMEP value at 1500

U U

rpm demonstrate the potential of a positivepumping loop, as with pressure compounding.

BMEP decreases because of increasing pumping and frictionlosseswith increasing speed.

Figure 49 shows the actual values of FMEP for each of three fuelquantitiesunder hotfiringconditions. These values are derived from the MEIS outputs for the IMEP

+12 u

and PMEP, and from dynamometer output for BMEP. The FMEP in this context does notinclude PMEP but does include all other mechanical losses.

In figure 50 friction MEP for an engine under load is compared with a motored enginefor a naturally aspirated environment. Both sets of data are plotted for friction values asdetermined from MEIS computation, where

FMEP = (IMEP _ PMEP)- BMEP.U

This comparison demonstrates the increase in friction MEP with an engine under load,compared with one that is motored under no-load conditions, lks shown in figure 51,FMEP values determined from motoring the engine are only slightly sensitive to inletboost conditions. The change in the slope of the line for naturally aspirated conditions isattributable to the change in inlet-to-exhaust pressure ratio. Figure 52 demonstrates theinfluence of load (increase in fuel quantity) on FMEP, and values are compared with two

motoring friction conditions operating under different inlet boost conditions. Real-timevalues of actual FMEP were 19 to 29 percent higher for the engine under load than for a

motored engine.

Figure 53 shows actual friction power values computed from a motored engine atthree inlet air pressures. Figure 54 compares the motored friction power value withvalues calculated from an engine operating under three loads to demonstrate the increasein actual friction loss with an engine under load. In conventional practice, however,motored friction values include the pumping losses. Figure 55, therefore, shows theequivalent values from the MEIS instrumentation for a motored engine by adding the

pumping power values to the friction power values at three inlet air pressures. Thesevalues are equivalent to those obtained by the conventional procedure of motoring theengine and show the influence of inlet air pressure on power loss across the speed range.

Pumping Mean Effective Pressure/power

With the MEIS instrumentation, it is also practical to quantify the difference inpumping work from a motored engine under different operating conditions and to comparethese values with those of an engine operating under load. Figure 56 compares the PMEPvalues from a motored engine under three inlet air pressure conditions and two inlet-to-

exhaust pressure ratios. Pumping power values for the same conditions are shown infigure 5? and demonstrate the increasing power loss due to increases in inlet air pressure.A comparison is made with an engine under load in figure 58. PMEP values from an engineunder load are shown to be lower than those of a motoring engine and insensitive toincreased load, or fuel quantity, at any particular speed.

Figure 59 is a composite plot showing the combined total of FMEP and PMEP for amotored engine at three inlet air pressures and for an engine operated at three loads and262 kPa (38 psia) inlet air pressure. For the same inlet and exhaust pressures, the valuesof FMEP + PMEP from a motored engine were higher than for an engine under load at allspeeds, except 3000 rpm where the two lines converge at higher load conditions (140

mm3/cycle).

Pressure Compounding

The concept of pressure compounding is intended to transform the negative work,normally contained in the pumping loop of the four-stroke thermodynamic cycle, to a

13

positive value. This canbeaccomplishedby adjusting the magnitudeof inlet-air andexhaust-gaspressures. Figure 60showsenlargementsof the pumpingloop diagrams forthe engineoperating at an inlet pressureof 262kPa andthree exhaustback pressuresandat 2000rpm. Figure 61showspumpingloop diagramsfor _heenginerunning at the samespeedbut with an Inlet pressureof 413 kPa. The summaryof thesedata (table VII)indicates that significant reductions in pumpinglossescanbe accomplishedwith higherpressureratios (PI/PE) acrossthe cylinder. Positive work output from the pumpingloopcanbe accomplishedby increasingthe inlet air pressure,by decreasingthe exhaustback-pressure,or by a combination of both methods. For this example,a 13percent reductionIn BSFCis obtained by increasing the inlet air pressure by a factor of 1.6 and by reducingthe exhaust back pressure by 40 percent.

Figure 62 is a plot of IMEP and IMEP _ PMEP versus exhaust backpressure for twoU U

speeds, 2000 and 2500 rpm, and four fuelquantltles: 80, 100, 120 and 140 mm3/cycle.

For 262 kPa inlet pressure, zero pumping load occurs at an exhaust backpressure of 154kPa for 2500 rpm and at 185 kPa for 2000 rpm, regardless of the fuel injected quantity orengine load. The IMEP is shown t_o be essentially constant at each load and speed setting

U

regardless of the pressure ratio (PI/:PE) value. The pressure ratio, however, does influenceBMEP values as shown in figure 63. The point of transition between positive and negativepumping loop values occurs at a pressure ratio of 1.4 for 2000 rpm and at 1.7 for 2500rpm. Figure 63 also shows the net gain in power, or BMEP, at four fuel quantities for

pressure ratios greater than 1.4 and 1.7 for 2000 and 2500 rpm, respectively. A 1.25pressure ratiowas used throughout thispro)ect to simulate back-

pressure from a conventional turbocharger. The percent increase in BMEP, by increasing

the pressure ratio from 1.25 to 2.62 maximum, is shown in table VIIIto be in the range of

3.4 to 6.7 percent £mprovement.

Pressure compounding is shown to provide the opportunity of improving overall engineperformance by controlling the inlet boost pressure and reducing exhaust backpressure.One method that can be effectively used on turbocharged engines is a "blow-down"turbine where each cylinder discharges independently to separate turbine nozzles and thendischarges to atmosphere.

Encoder Mtsalignment Effects

Figure 64 shows the effect on IMEP readings with the modular engine instrumentation

system (MEIS) ifthe encoder zero crank angle signalisnot set at exactly top dead center

of the cylinder. These plotsdemonstrate the importance of precisionwhen settingup the

encoder. The error can be greater than 11 percent for a I° misallgnment. The encodcr

signalwas displaced electronicallyfor thisdemonstration.

C ONC LUSIONS

Inlet Pressure Effects

1. Optimum engine performance (BSFC and BMEP) occurs at approximately 329-kPainlet air pressure when the cylinder pressure ratio is maintained at 1.25, representative ofbackpressure from a typical state-of-the-art turbocharger system.

2. Peak cylinder gas temperature is an inverse function of inlet air mass andproportional to load or fuel quantity per cycle.

Inlet Temperature Effects

14

3. Volumetric efficiency is a misleading parameter for supercharged engines. BMEP

and BSFC are more meaningful indicators of engine performance at different inlet air

temperatures.

4. Optimum injection timing for BSFC and BMEP is not influenced by inlet air

temperature.

Exhaust Emissions

5. Calculated values for total particulate mass, based on exhaust smoke opacity,correlate best with the solid fraction of the total measured particulate matter. The

soluble organic fraction of the total measured particulate correlates more closely with

the hydrocarbon emission measurement than with smoke opacity.

6. Both total particulate matter and hydrocarbon emissions decrease with increased

load between 1500 and 3000 rpm.

7. The lowest levels of exhaust smoke and gaseous emissions occur with inlet air

pressures greater than 372 kPa, while maintaining the pressure ratio at 1.25.

8. Operation at 2500 and 2000 rpm with Jet A fuel resulted in lower oxides ofnitrogen emissions and peak cylind_r g_s pressures, but higher hydrocarbon emissions, than

those obtained with DF-2. At 2500 rpm, BSFC, BSCO, and total particulate mass emis

sions were lower with Jet A fuel, but at 2000 rpm, these emissions were lower with DF-2fuel.

Modular Engine Instrumentation System (MEIS)

9. Use of MEIS instrumentation requires accurate precision when timing the shaftangle eneoder signal to the engine for top dead center location. Errors greater than 11

percent of net IMEP can result with 1 ° crank angle misalignment.

10. MEIS instrumentation provides a more accurate and convenient method forreal-time measurement of friction power than by the conventional motoring method.

11. Positive work output from the pumping loop can be obtained either by increasingthe inlet air pressure, by decreasing the exhaust backpressure, or by a combination of both

methods. A 13-percent improvement in BSFC was shown by increasing the pressure ratio

from 1.25 to 3.33 at 2000 rpm.

.

.

.

.

REFERENCES

Funkenbusch, E.F.; Leddy, D.G.; and johnson, J.H.: The Characterization of the

Soluble Organic Fraction of Diesel Particulate Matter. SAE Paper 790418, Feb. 1979.

Rice, W.I.; and Birchenough, A.G.: Modular Instrumentation System for Real-TimeMeasurements and Control on Reciprocating Engines. NASA TP-1757, 1980.

Taylor, Charles F.: The Internal- Combustion Engine in Theory and Practice, Vol. II:

Combustion, Fuels, Materials, Design, MIT Press, 1968.

A Laboratory Comparison of In-Line and End-of-Line Full-Flow, Diesel Smoke

Opacity Meters. CRC-APRAC-CAPI-1-64, Coordinating Research Council, Inc.,

1977, (PB-278 076).

15

S°

.

Vuk, C.T.; lones, M.A.; and lohnson, I.H.: The Measurement and Analysis of thePhysical Character of Diesel Particulate Emissions. SAR Paper 760131, Feb. 1976.

Greeves, G.; and Wang, C.H.T.: Origins of Diesel Particulate Mass Emissions. SAEPaper 810260, luly 1981.

16

TABLE I. - EXHAUSTGAS ANALYSIS INSTRUMENTS

Constituent Type of instrument Measurement range

!co

CO2

NO/NOx

HC

O2

Nondispercive infra-red

Nondispercive infra-red

Heated chemiluminescence

Heated flame ionization

Paramagnetic

0 to 2500 ppm, 0 to I0 percent;

3 ranges

0 to ]5 percent; 3 ranges

0 to I0 000 ppm; 9 ranges

0 to lO 000 ppm; 8 ranges

0 to 25 percent; 4 ranges

TABLE II. - SPAN GAS BOTTLES

Span gas Concentration

C3H8 in air

02 in N2

CO2 in 02 Free N2

NO in N2

!NO in N2

14.8 ppm

29.6 ppm

152 ppm

304 ppm

8 percent

2.42 percent

3.96 percent

13 percent

I197 ppm

1 percent

4.05 percent

36.5 ppm

455 ppm

820 ppm

4090 ppm

TABLE Ill. - SPECIFICATION AND OPERATING GUIDELINES FOR

PARTICULATE MEASUREMENT

Standard conditions

Temperature, °C (°F) ........................ 20 (68)

Pressure, kPa (in. of Hg) .................. lOl.3 (29.92)

Filter size, mm diam ............................ 47

Pump displacement per revolution, m3 (ft3) ............ 0.017 (0.6)

Probe flow rate (maximum), liter/s (scfm) ............. 0.47 (l.O)

Filter flow rate (minimum), liter/s (scfm) ............. 9.8 (0.35)

Probe temperature (maximum), °C (°F) ................. 52 (125)

Filter loading, mg ........................... 2 to 7

TABLE IV. - MAJOR MEASURED PARAMETERS

Parameter Instrument Full scale value

Fuel flow 0.037 kg/s (tp Ib m/hr)

Engine airflow

Engine torque

Engine speed

Cylinder pressure

Injection pressure

Engine inlet air

pressure

Engine inlet air

temperature

Blow by

iEngine exhaust

pressure

Engine exhaust

temperature

Hydraulic wheatstone bridge

mass flowmeter

Turbine type flownmter

Load cell on the dynamometer

Magnetic pick-up

Water-cooled piezoelectric

quartz transducer

Strain gage transducer

Strain gage transducer

Chromel alumel thermocouple

Displacement type flowmeter

Strain gage transducer

Chromel alumel thermecouple

47 liter/s (I00 scfm)

347 J (256 ft-lb)

6144 rpm

27.6 MPa (4000 psig)

69 MPa (lO 000 psig)

765 kPa (Ill psia)

121 ° C (250 ° F)

8.5xlO'4m3/s (1.8 scfm)

690 kPa (I00 psia)

1024° C (1876° F)

TABLE V. - BASELINE EMISSIONS

[Injection timing set for optimum performance]

Fuel

quantity

mm3/cycle

Number Brake mean Air to

of effective fuel

tests pressure, ratio

BMEP,

kPa (psi)

Brake specific emission, g/kW-hr (standard deviation)

CO HC NOx Particulates

Measured Calculated

Engine speed, 1500 rpm

Soluble

organic

fraction,

SOF,

percent

60

80

I00

120

140

612 (89)

869 (126)

1124 (163)

1350 (196)

1551 (225)

79.5 3.67 (0.30) 2.71 (0.29) 15.78 (0.12) 1.33 (0.39)

58.9 2.25 (.36) 1.89 (.17) 18.41 (.15) I.II (.46)

47.2 1.65 (.12) 1.37 (.07) 20.48 (.76) 0.75 (.07)

39.3 1.92 (.21) 1.17 (.04) 19.86 (.44) .78 (.05)

33.8 2.3| (.19) 0.95 (.03) 18.36 (.72) .75 (.04)

0.40

.23

.27

.43

.63

49.4

63.3

62.8

37.1

i

60

80

I00

120

140

Engine speed, 2000 rpm

8 521 (76) 74.2 4.65 (0.15)12.97 (0.47) 15.76 (0.68) 1.77 (0.36)

I0 785 (114) 54.9 2.45 (.24) :1.92 (.16) 15.73 (.37) 0.99 (.28)

10 1027 (149) 43.8 1.81 (.24) .64 (.16) 17.63 (.27) .96 (.19)

I0 1267 (184) 36.4 2.14 (.46) .26 (.II) 18.88 (.87) .78 (.27)

9 1437 (208) 30.8 3.85 (.16) 1.23 (.05) 18.40 (.27) 1.26 (.03)

0.44

.25

.30

.40

1.02

75.3

74.1

76.9

52.4

Engine speed, 2500 rpm

60

80

I00

120

140

I0 418 (61) 64.7

7 692 (lO0) 49.6

13 968 (140) 39.3

II I184 (172) 33.1

6 1374 (199) 27.9

6.19 (0.86) 3.58 (0.42)

3.08 (.91) 2.13 (.34)

2.61 (.70) 1.65 (.31)

3.60 (1.26) 1.39 (.17)

4.65 (.31) 1.18 (.16)

21.25 (1.26) 2.52 (0.66)

17.55 (.56) 1.58 (.66)

17.93 (.46) I.II (.36)

18.34 (.51) 0.94 (.ll)

16.94 (2.61) 0.91 (.04)

0.46

.37

.43

.35

.62

78.0

78.7

60.5

56.3

Engine speed, 3000 rpm

60

80

I00

120

140

4 355 (51) 63.9

6 590 (86) 46.5

6 830 (120) 38.0

7 1057 (153) 32.3

6 1287 (187) 27.3

7.30 (0.79)

4.25 (.50)

3.39 (.06)

3.83 (0.72)

5.64 (0.23)

4.65 (0.54)2.52 (.25)1.84 (.05)1.47 (.15)1.03 (.05)

20.29 (0.78)

16.60 (.80)

15.25 (.29)

14.54 (.40)

15.50 (1.61)

2.05(0.50)1.33(.35)1.19(.13)0.91(.05)0.94(.04)

0.81

.52

.68

.68

.78

80.1

58.9

37.2

25.2

Property

TABLE VI. - DIESEL AND JET A FUEL CHARACTERISTICS

Gravity, °API

Specific gravity

Heat content of fuel:

Gross, MJ/kg (Btu/Ib)

Gross, MJ/m 3 (Btu/gal)

Net, MJ/kg (Btu/Ib)

Hydrogen to carbon ratio

Hydrogen, wt %

Carbon, wt %

Sulfur, wt %

Cetane index

Aromatics, vol %

lOlefins, vol %

Saturates, %

Distillation, °C (°F)

Initial boiling point, °C (°F)

10%,

50%,

90%,

End point,

Kinematic viscosity, C S (m2/s)

Flash point, °C (°F)

Cloud point, °C (°F)

Pour point, °C (°F)

Aniline point, °C (°F)

(ASTM) test method

D-287

D-1290

D-240

D-240

Calculation

Diesel control fuel

34.696

0.8514

45 (19228)

37 976(136375)

42.0(18043)

Calculation

Chromatography

Chromatography

D-129

D-976

D-1319

D-1319

D-1319

D -86

D-86

D -86

D-86

D-86

D-445

D-93

D-2500

D-97

D-611

1.777

12.98

86.85

0.31

47.8

29.61

1.40

68.99

191 (376)

219 (426)

264 (508)

302 (576)

315 (599)

3.6/

73 (163)

-Ig (-2)

-41 (-42)

60 (14o)

Jet A

42.58

0.8128

45.5 (19 561)

36 880 (132 438)

42.6 (18 312)

1.905

13.69

86.25

0.063

47.3

15.21

0.78

84.08

160 (320)

184 (364)

214 (418)

251 (484)

273 (524)

2.0

49 (120)

-20.6 (-5)

-51.7 (-61)

62 (144)

Inletair

pressure,kPa (psia)

262 (38)

262 (38)

262 (38)

414 (60)

414 (60)

414 (60)

TABLE VII. - PRESSURECOMPOUNDINGRESULTS AT 2000 RPM

[Engine speed, 120 mm3/cycle]

Exhaust

pressure,kPa (psia)

210 (30)

152 (22)

110 (16)

331 (48)

207 (30)

124 (18)

Pressureratio

1.25

1.72

2.40

1.25

2.00

3.33

Mean effective pressures, kPa (psia)

Indicated,

IMEPu

1588 (230)

1588 (230)

1578 (229)

1613 (234)

1620 (235)

1613 (234)

Pumping,PMEP

-37 (-5.5)

+25.5 (+3.7)

+67 (+9.7)

-41.4 (-6)

+76 (+ll)

+138 (+20)

IMEPu + PMEP

1551 (225)

1613 (234)

1645 (239)

1572 (228)

I696 (246)

1751 (254)

Brake

specific

fuel con-

sumption,

BSFC,

kg/kW-hr

0.217

.208

.202

.213

.195

.188

TABLE VIII. - MEAN EFFECTIVE PRESSURE AT TWO

PRESSURE RATIOS

Engine

speed,

rpm

200O

2500

Fuel

quantity,

mm3/cycle

Pressure ratio

1.25 2.62

Brake mean effective

pressure, BMEP, kPa (psi)

80 ....................

100120

140

8O

I00

120

140

1065 (154)1300 (188)1500 (217)

750 (109)1020 (148)1265 (183)1485 (215)

1135 (164)

1365 (198)

1580 (229)

800 (116)

1070 (155)

1315 (191)

1535 (223)

Increase

in BMEP,

percent

6.6

5.0

5.3

6.7

4.9

4.0

3.4

Figure 1. - Single-cyclinder test engine installation,

c.)

to

-=,

2.0

1.5

1.0

.5

m

Instantaneous plunger velocity - S{Cx rpml/lO00 mlsec

-,/ _

..7 II /\',\ _

I0 20 30 40 50 60

Cam angle,(leg

Figure2.-Injectionpump cam analysis.

E

E

E_haustFilter

]_S Heated sample

I line

I lransferSingle pumpscylinder test

en_jine

(a) Data handling schematic.

[','- - -vlisplay

Minicomputer

# ,V

Remote Jacquisition

microprocessor

Sample

i

Sample

purge

Purge

gas

C_ Pressure regulator '-_ Relief valve

Solonoid valve E3 Filter

_I Flow valve _ Control valve

_] Flow meter 0 GageL'_ Boost pump

Exhaust stack

_ Pyrometer

Span gas

HC

free

HC air Air Fuel

_Hydr_artlons F

Vent

Air

filter

, OxygenNO2 CO 0 2 CO2

o 0 0

I _ su_

tank

] VacuumI pump

Dryer _j,

Vent

N2 zero gas 0 2 span

Ibl Flow schematic.

Figure 3. - Exhaust gas analysis system.

Figure 4. - Particulate sampling system.

E×haListt

Vent Electric F _@___._ _"'r _ heater --13

:,upply ...... _--I 4°C --lJ, ;?let

F,ter_--_:&--"_-JprobesI In-icasse,eII i! ! r--P", ' i_ opac,,_meter

II Ii I "JJ-' By-pass V f A.... er II _ En_,ne

Vacuum ,_ _E×haust

pump z._ p _ . thr,,

I I Flowmeter L j U.ffle r r{)l)f

_m.._cFM totalizer .4:L0 _i'ute I I In-line

I I °mcitY1 sample To t I_ meier

emissions •

analyzer I_

-lines l] F] -

maintained V -_ h_. ]]900 C

Ibt Emission sampl ng system.

Figure 5. Test operator console, inslurnmntpanel, ande×haust emissions console.

Engine

speed,

1600 ]OOO 0 rpm2000

lsooL__ t _est_aci,,,.kscRE

,ooo/___ 'oo/-- 'ac',,e,'s,,,_""" .._ _../ _ / ./4.. ,,,.._,.

.o_----o----'o--40OL... zoo L......._ "

-L-___c___= 8

46

c}_cj

tc_

.£ zoo/--

=- / Fuel•_ t quantity

/ lZO_40 _6o _8o zoo z¢o

-_ / _\\\ \\

F" orake meanefle_t_v_._16OO 1800

-_- restdataversus , BMEt. kPa 2200

manufacturer supplieddata.

c:

Eo

120 --

100--

80--

6O

/- Inlet

I I I I(a) As-received engine.

120 --

I00-- s....

80--

6o I I I I I1000 1500 2000 2500 5000 3500

Enginespeed,rpm

(bt Modified andretuned engine.

Figure 7. - Volumetric efficiencyversus engine speed- effect ofinlet manifold pressure resonance.

0

,,=,o-

.__ 4

D

Inletair

pressure,kPa

0 195__ [3 262

Z_ 329

0 372

I I I "--Y- I _ I I Ila) Engine speed, 3000rpm.

lb) Engine speed,2500rpm,

8

0 I200 400 600 800 1000 1200 1400 1600 1BOO 2000

Brake meaneffective pressure, BMEP, kPa

(c) Engine speed, 2000rpm.

Figure 8. -Effect on air-to-fuel equivalence ratio with increasinginlet air pressure at different BMEP's.

3OO0

i1000

ca_-

:_ 100fl

_ oE

0= 2000

1000 f

0150

Fuel

quantity,

mm31cNle

O 6O[] 80

A 100r,. 120

140

_3 160O 180

<> 200

(a) Engine speed, 3000 rpm.

,o----To ' i ,o--7-o_[--lb) Engine speed, 2500 rpm.

_1 1--1250 350 450

Inlet air pressure, kPa

(c) Engine speed, 2000 rpm.

Figure 9. - Effect on B/V[P with increasing inlet air pressure.

I550

120 --

80 --

40 __

0 --

Engine Fuelspeed, quantity,

gO -- rpm mm31¢_:le

0 2000 200-- 180.60 [i] 2500

A 3000 140. l_,t_<_CC'-_

30 -- I00_

6oi.c_.._ i -i_ 1"8o. I I I0200 400 600 800 1000 1200 1400 1600 1800 2000

(a) Inlet air pressure, 414kPa.

6080 --

60 --

40 -- 30

20 --

0 --

20O

120100

o l I I I I I I I b200 400 600 800 i000 1200 1400 1600 1800 2000

_" _ (b) Inlet air pressure, 372kPa.J o"Q-- Q_

= 120 -- = 90 f---

!::3 :3

80- _ 60_ 140 160 1so...__

600 800 i000 1200 1400 1600 1800

80 --

60--

4O--

20--

oi_

(c) Inlet air pressure, 329 kPa.

60--

4O

2O

I2OOO

1,ojL_

80

I I J I0 500 1000 1500 2000

(d) Inlet air pressure, 262kPa.

72--60 r---

II 140

Brake mean effectivepressure, BMEP, kPa

(e) Inlet air pressure, 193 kPa.

Figure 10. - Effect of engine speedon brake poweroutput.

f2OOO

i

t30

o

o:

Inlet

air

pressure,

.60 kPa

0 193

D 262

A 329

.40LO_ 0 372

• 20 --(a) Encjine speed, 3000 rpm.

• 4O

• 2OIb) Engine speed, 2500 rpm.

.30

.20 "-[

200 400 600 800 1000. 1200 1400 1600 1800 ZOO0

Brake mean effective pressure, BMEP, kPa

(cl Engine speed, 2000 rpm.

Figure 11. - Effect on BSFC with increasing inlet air pressure at

different rpms.

35

3O Inletair

pressure.25 kPa

O 193

[] 262

A 329

20 (3 3/2

0 4t4

15 I J ]

200 600 1000 1480 1800 22OO

(a) Engine speed, 3000 rpm.

40c_.

30

_, 25

20200 600 looO 1400 1800

Ib) Engine speed, 2500 rpm.

t22OO

45

40

35f3O

252OO

fI I I I

6OO 1000 1400 1800

Brake mean effective pressure, BMEP, kPa

ic) Engine speed, 2000 rpm.

Figure 12. - Effect on brake thermal efficiency with in-

creasing inlet air pressure at different rpms.

I22OO

Enginespeed,rpm

0 2000

E3 250020. 0 -- A 3OO0

__Maximum allowable cylinder pressure

19.5--

19.0

18.5

18.0 I

200 400 600 800 1000 1200 1400 1600 1800 2000

(a) Inlet air pressure, 414 kPa.

20 -- 0

19

18

=E 17

I16 --

o 200 400 600 800 1000 1200 1400 1600 1800 2000

._ tb) Inlet air pressure, 372 kPa.

0I_" 19

18

17 I400 600 800 i000 1200 1400 1600 1800 2000

{c)Inletairpressure, 329 kPa.

20 --

16 --

12 --

8I I I I

400 800 1200 1600

Id) Inlet air pressure, 262 kPa.

I2O00

11

9 _ i 1 I I I I I200 300 400 500 600 700 800 900 1000 1100

Brake mean effective pressure, BMEP, kPa

(e) Inlet air pressure, 193 kPa.

Figure 13. - Effect of engine speed on peak cylinder gas pressures

at different inlet air pressures.

35OO

3000

o

2)0(3

._ 2000£

1500

l--- Inlet

air Fuel

pressure, quantity,kPa mm31cycle

2000 0 193 140__ 0 262

ZX 329 /__ 0 372 I20r(

1800 0 414/ \

1600--

! "1400

1200

g. IOO0

-- 800 I I I I I I t I I200 400 600 800 1000 1200 1400 1600 1800 2000

Brake mean effective pressure, kPa

Figure 14. - Effectof inlet air pressure on peakcylinder gastemperature. Enginespeed, 2000rpm.

3000

[

2000__

I000 L

4O0O

0

o<_,

35oo[- _ 200o

"_x 3000_-

250o_- __1500

2®0[ g 1o®150o

>.,

Enginespeed, Fuel

L rpm quantity,0 2000 mm3/cycle

1600 El 2500 160 1%

! A 30O0 140

ii 120 _ /

1200_-- 8A_ J /__

400[ I I I I [ J I I I200 400 600 800 1000 1200 1400 1600 1800 2000

(al Inlet air pressure, 414 kPa.

2000 --

140 160 180

i000 --_

o J I J I i J I I I200 400 600 800 1000 1200 1400 1600 1800 2000

tb} Inlet air pressure. 372 kPa.

4000

3500 _- 2000

3000 Ir---1500

2500 --

2000--

1500

4000--

3500 -

5000--

2500 -

2000 --

I 1 L J 1 1 I I I.E_ 5.400on, 600 800 i000 1200 1400 1600 1800 2000 2200

Ic) Inlet air pressure, 392 kPa.

2500 --

160 180

-- 120 _

_ 100_z_:_'_ _

5_oo1"_2 I I I I I I I I400 600 800 I000 1200 1400 1600 1800 2000

tdlInletairpressure,262 kPa.

2500--

80

1500 -- 60

looo I200 300 400 500 600 700 800 900 1000 1100

Brake mean effective pressure, BMEP. kPa

lel Inlet air pressure, 193 kPa.

Figure 15. - Effect of engine speeO on cylin6er gas temperature.

1 I I I_ _ _ _ o

gd_l 'd3W_] 'gJnsSgJd a^!l.:)gJJg uggw g)IgJ9

tatJ "--

I J Io

OE3<I GO

_g

I I I

I I I I

_" _o

I I I I i

O0 'gJn]gJadwg]. Se6 Isneqx3

I I I I I [

'aJnleJadLualse5 Isneqx3

I I I

I I I

o_

_i. } _

Y_i

o ,d,

Oo

I

L_-

m

lua_Jad '/(auap!jja II_W.laqla_leJ8

D

o

g

_.o_"L_

OQ<_O0

o

I I

ilJLI-/VglI5 '3-IS8 'u0p,duJnsu0_lanj 3!Jpadsa)IE'J_

§o_

,o_

"T

o

i

E

lo I I I I(a) Peak cylinder gas pressure.

E

E

c

>,

3500 --

3000 --

E

2500-

zooo-

1500 --

2000 --

1800

1600

1400

1200

1000

800 I I i I20 40 60 80 100

Air-to-fuel ratio, AIF

ib) Peak cylinder gas temperature.

Figure 20. - Peak cylinder gas pressure and temperature versus air-to-

fuel ratio. Engine speed, 2000 rpm.

I120

--- ¢._

E

2

E

P=,.

d o=

8

._-:'= _I:.= E

E -

i

g _

o=

Static

injection

timing,24 -- deg

Optimum

t imi ng -,_ 42

FTDC """"--. _" .-...." ""0 _ "---26

_" 22

s I I I I1000 1500 2000 2500 5000

Engine speed,rpm

Figure 22. - Staticversus dynamic injection

timingcorrelation.

r_

(...3

-00

-4o

-2O

-60 --

-40 --

-20 --

0

-60 i

0 Static timing0 Beginning of pressure riseA Beginning of injection[] Beginning of ignition

elay

I I , I(a) Fuel quantity, 140 mm3/cycle.

O.....-_I I , I

(b) Fuel quantity, 120mm31cycle

-4O

-7O

-60 --

.......--o--f

(c) Fuel quantity, 100 mm3/cycle.

-4O

-20

-60 --

o--"I I--o

(d) Fuel quantity, 80 mm31cycle.

-40

-20 --

000

E3_, I , I

2000 3000Engine speed, rpm

(e) Fuel quantity, O0mm31cycle.

Figure 23. - Diesel fuel injection variables. Injectiontiming setfor optimum performance.

O

\

_" E

I I

o

_E

I

_1 C I

o o _._-_ _ "_

N_

N_N _

N

Jq-NgI/6_ '3-1SB'u0!IduJnsu0_lanj 31jF_adsa)leJ_]

cr

o n<_ z__q

_qAy /q

i I i I

edit 'd3W8 'aJnsSaJd@A!]:)aJJ8ueauJa_leJB

'_ o_o ~ _

'__•_, _._

iN }_

300

28O

26O

240

-E 200

180

160

Enginespeed,

rpm

1500

_ 0 2000

20 40 60 80 100 120

Inlet air temperature, °C

I I I I100 150 200 250

Inlet air temperature, OF

Figure 26. - Inlet air mass as function of inlet

air temperature. Inletair pressure, 262 kPa;

fuel quantity, 100 mm31cycle.

E

1400

1300--

1200 I-25 0

I I I t-20 -15 -10 -5

(al Fuel quantity, 140mm31cycle; engine speed,2000rpm.

950 -850 I l

-25 -20 -15 -lO -5 o(b) Fuel quantity, 100mm3tcycle; engine speed, 2000rpm.

520 --

480--

440--

400-25

1400

1000 _ I-20 -15 -10 -5 0 5

(d) Fuel quantity, 140 mm31cycle; engine speed, 2500rpm.

850

75O

I650_ -15 -I0 -5 0 5 i0

(e) Fuel quantity, 100mm31cycle; engine speed,2500rpm.

Inlet air

550 -- temperature,

oc450 -- 0 3;'.8

I-I 65

//-TDC 350 -- _t lOl

I I I I I 250 I I I I-20 -15 -10 -5 0 5 -20 -15 -10 -5 0 5

Injection timing, deg before top deadcenter

(f) Fuel quantity, 60 mm31cycle; engine speed, 2500rpm.(c) Fuel quantity, 60 mm31eycle; engine speed, 2000rpm.

Figure 27. - Effect of inlet air temperature on BMEP. Inlet air pressure, 262kPa.

I10

i

cx_

o===.E

.26 --

.24 --

I I I I!'20-2_20 -15 -10 -5 0

(a) Fuel quantity, 140mm3/cycle; engine speed, 2000rpm.

.30 F

.22-25 -20 -15 -10 -5 0

(b) Fuel quantity, 100 mm31cycle; engine speed, 2000rpm.•38

•34

•30 --

.26 I-25 5

_TDC

-20 -15 -I0 -5 0

Inlet airtemperature,

oc0 37.8

•30 -- [] 65 /_,¢c_

"Z2-21 -15 -i0 -5 0

Id) Fuel quantity, 140 mm3/cycle; engine speed, 2500rpm.

24 _-20 -15 -10 -5 0 5

(e)Fuelquantity,I00mm31cycle;enginespeed,2500rpm.

II0

•60

.50

.40

.30-20 -15 -10 -5 0 5 [0

Injection timing, (legbefore top deadcenter

(c) Fuel quantity, 60 mm31cycle; engine speed, 2000rpm. (f) Fuel quantity, 60 mm3lcycle; engine speed, 2500rpm.

Figure 28. -Effect of inlet air temperature on BSFC. Inlet air pressure, 262 kPa.

0

C..)

Ut,:

8

6

5

4--

3--

2 --

i2OO

Engine

I speed,

rpm

0 1500

O 2000

A 2500

I I I I I I I400 600 800 1000 1200 1_ 1600

Brake mean effective pressure, BMEP, kPa

B n

7 -- Fuel

quantity, A_

6 -- mm31cycl_ r

21

1 i I I t I I1500 1750 2000 2250 2500 2750 3000

Engine speed, rpm

I3250

7

6

/ /_ quantity

,\ / /3

2 100

i I I 12ol I I I I20 30 40 50 60 70 80 90

Air-to-fuel ratio

Figure 29. - Baseline carbon monoxide emissions.

Engine optimized for performance. Inlet air temper-

ature, 34o C ; inlet air pressure, 262 kPa.

2 --

4

3

g

T=<,> 2

1200

Engine

speed,

rpm

© 1500

rn 2000

A 25O0

C3 3000

400 600 800 1000 1200 1400 "'1600

Brake mean effective pressure, BMEP, kPa

Fuel /quantity,

_ mm31cy cle

I I I I I I I1500 1750 2000 2250 2500 2750 3000 3250

Engine speed, rpm

5 m

60{

4 -- Fuel /_

quantity, / .,_\

3-- mm3/cycle / / x_,/

o I 1 I I J I20 30 40 50 60 70 80

Air-to-fuel ratio

Figure 30. - Baseline hydrocarbonemissions. Engineoptimized for performance. Inlet air temperature,34o C ; inlet air pressure, 262 kPa.

i

5i=n

o=

E

o _Z

22

2O

18

16

t4 I200 400 600 800 1000 1200 1400 1600

Brake mean effect ve pressure, BMEP, kPa

Fuel22 -- quantity,

20 __

18 I

14 I I t I I _12°11.500 1750 2000 2250 2500 2750 3000 3250

Engine speed, rpm

2O

18

16

14

2_r-

Engined_ \ / // speed,

! _ )/k_/ rpm""A\ / _ 0 1500_ \ [] 2ooo

- "1, -/ \ _ 2_

J f I I 1 L J20 30 40 50 60 lO 80 gO

Air-to-fuel ratio

Figure 31. - Baseline oxidesat nitrogen emissions.Engine optimized for performance. Inlet air temper-ature, 34oC; inlet air pressure, 262kPa.

i

_5

o=

2.6

2.2 --

1.8

1'4 t

1.0

.6200

,5 Enginespeed,

rpm

4OO 600 800 1000 1200 1400

Brake mean effective pressure, kPa

2.6

2.2

1.8

1.4

1.0

I1600

2. 6 -- 60

2. 2 -- Fuel //

quantity, / C_

1.8 mm3lcycle /S _3-- 80

.6 I \1 "'t I I I I20 30 40 50 6U lO 80 90

Air-to-fuel ratio

Figure 32. - Measured total particulate emissions.Engine optimized for performance. Inlet air temper-ature, 34oc; inlet air pressure, 262kPa.

Fuelquantity,

.6 11500 1750 2000 2250 2500 2750 3000 3250

Engine speed, rpm

i

ct_

W

1.2 --

1.0 --

.8 --

• 6 --

.4 --

.2

Engine

speed,

rpm

O 1500 O

O 2OOO

A 2500

O 3O06

aO

(3

AO A D[] O

AA

ogI P t I I

0 .5 1.0 1.5 2.0 2.5

Measured brake specific particulate emission,

g/kW-hr

Figure 33. - Measured total particulates versus

calculated particulates. Engine optimized for

performance. Inlet air temperature, 34o C;

inlet air pressure, 262 kPa.

14

12

10

_- 8

68-

4

-- Engine

speed,

-- rpm /

0 1500

-- 0 2000

A 2500

-- [] 30OO A

2 0

I I I I0 .2 .4 .6 .8 1.0

Calculated brake specific particulate emission,

g/kW-hr

Figure 34. - Calculated brake specific particu-

late emissions versus percent smoke opacity.

Inlet air temperature, 340 C; inlet air pres-

sure, 252 kPa.

4

i

n-

_ 2

m 1

5 --

-- ZX 121

A ine

[] O/ speed,

/ rpm-- rn_ O 1500

/A-- [] zooo

_AU A 2500

I I I I I I I.5 1.0 1.5 2.0 2.5 3.0 3.5

Calculated soluble organic mass fr_tion, g/kW-hr

Figure 35. - Measured soluble organic fraction of total particu-

lates versus hydrocarbon emissions.

g

8

2.1

2.2

1.7

1.2

A ngine

[]^/ speed,

-- 7 rpmE O 1500

0 2000

A 2500.7 r_ _ 3000

._ I I I I.5 1.0 1.5 2.0 2.5 3.0

Measured brake specific particulate emission,

BSPM, g/kW-hr

Figure 36. - Measured total particulates versus

calculated total particulates lexhaust smoke

opacity and total HC emissions).

JLt-M_I/6 'uo!SS!wa

03 3!t!:)ads a_EJ1]

Jq- M)I/6 'uo!ss!wa

3H 3!}pads a_EJl]Jq- M)II6 'uo!ss!waxON 3!t!:)ads a_E_8

Jq- M_II6 'uop,dw nsuo3

lanl 3!lpads a_RJI]

Io

J q- M)II6 'uo!sS!wa

09 :)!]!:)ads a_tEJ8

_._

",_E o

Mu_

,_3

Jq-M_/6 'uo!ss!wa Jq-_A)lt_ 'uo!ss!wa Jq-M)I/B 'uo!_dumsuo:)

OH _!J!_ads a)IEJ 8 xON 3!_!_ads a)ll_J9 lan,I _!Jpads a)lEJ

_ "_Eo

_ o, cN

c:_ . u_ t..,--' u_ "_ "_

'- E" ,._:Z _ .E

o _ c

_ c t o

Jq-M'4/6 'uo!ss!Ela Jq-/Vgl/6 'UO!SS!LUa Jq-ADI/6 'UO!SS]LUa Jq-_)ll6 'Uo!IduJnsu03033!Jpads a_lej8 3H 3!j!3adsa)leJ_] xON 3!j!3ads a)leJ£ lanj 3!ipads a_lej_]

Loo

\

iC

Jq- _)l/B 'uo!ss!uJa03 3!_!:)adsa)lej8

ce _ _o

/

L. I

JLI-t_116 'uo!ss!uJa3H 3!]!3ads a)lej8

I l__ I

Jq-Ngl/6 'uo!ss!uJaxON3!jpads a)leJ£

L

_._ ._

oe ge_

_dZ

_ c

Jq-/VgI/_ 'uo[Idu_nsuo_lant 3!t!_ads a_l_J8

o @E£

wdd lua3Jad wdd

lua3lad '/(l!:_d 0 'uo!ss!uJa xON 'UO!SS!LUa(]3 'UO!SS!LUO3H

I

Jq-_.316 'UO!SS!Wa Jq-/_ll6 'uo!ss!wa JLI-M)IID 'uo!ss!tua Jq-_)_16 'uop, duJnsuo303 _!j!_ads _)l_J8 3H 3!i!3eds a_J_] xON _!j!3ads a_l_J_] lanl _!j!_ads a_l_J_]

m

<3 0 __._

\ _-_

NN

0 O<3 __ "°°_°_'=o.__°_'_

_¢,.J_ o _ _ o_ o_lua3Jad ),uaJJad todd'/_l!JEd 0 todd 'uo!su!wa xON 'uo!_u!wa (]3 'UO!_S!LUO3H

m

II

__ I

lua_Jad todd _uaJJad'XU_Ed0 'uo!ss!wa×ON 'uo!ss!wa03

@

wdd'uo!_!wa 3H

§_ ._N N_

¢o

<

<

,g

°

_._ <_ "_

i

E:) ¢'M

o

E

_.o _-,_,_ __E

OD_GO

I t

°\ " Ei

uJdd _ue_Jad

'uo!ss!uJaxON 'uo!ss!LueO:D

I

>-,E

0 E'-E E

o _

.___'_

_0_'_ _o.®_

_ ' ._o

o_ cr

wdd

),ue_Jed',(Ipedo 'uo!ss]uJe OH

o=,uE

O

,m

o"-j,

¢¢a

o=

E

cad

$ _ Engine Fuelspeed.rpm

O 20OO !6 Z_ 2500 (JetA

O 2500 Die_l 2

I

o I t I 1

140

pb

/

I ,J

27

2O

18

3.6

14

12

10

240 --

230

220_

210900

I J J J I_

II000

1.4

_1.2

o't

o=_I.0

-g

.__

a.

.6

_t

,, J

Fuelquantity,mm31cycle

/

I\

cn

-,r"

I00 120 140

- ( _

/

I ----F j J

llO0

140

I

I J1200 1300 1400 1500 900 I000 llO0 1200 1300 1400 1500

Brake meaneffectivepressure, BMEP, kPa

Figure 47. - Exhaust emissionsand fuel consumptionresults with JetA and diesel fuel.

c:_ L_

+L

OD<_

I I _

E

@

v

E

edW 'd3W 'ajnssaJd aA{l_aJJa ueaw

c_

e_

I L

c

E%

c_ _ '! " _i

__ ,_

L _ __-,"

,'1 .>I

ca

,'I )I 4]

I _ ? I _

1{

c_J

_clW 'n cl3Wi

'ajnssaJd _^{|3_J_lU2_UJpa_{PUl

fI

•_r e,a

edW

' d3Wcl _ n d3WI 'aJnssaJd a^!_jJa

UeaLUclool 6u{duJnd Snld dOOlJ_dN

/

_ID ,,or

_d_ 'd3W_

'aJnssaJd a^p,_gjJa ueauJ 8_leJ8

L_J B

o) _ m

.__ _ ._

iZ

LL.

C_

E

o=

u-

11Fuel

quantity,mm;Icycle

E_ 0A 60

-.4 ] .... --[ I _ I1400 1800 2200 2600 3000 3400

Engine speed, rpm

Figure 50. - FMEPvalues versus engine speedfor a naturally aspiratedengine in both motored and hot firing operation.

=_"

LL

E

.__

o=

-.5

-.10

-.15

-. 20

-.25

-. 30

-. 35

Inlet Exhaustair pressure,

12_ pressure, kPa

-- _ kPa

E3 100 100[] 262 210

_ 0 414 331

I I I I 1 _500 1000 1500 2000 2500 3000

Engine speed, rpm

Figure 51. - FMEPversus engine speedfor motored engine.

c,."

E

==

o_

t..u-

Fuel Inlet

quantity, airmm>lcycle pressure,

kPa

O 60 l-.15- A 100 262

(3 120

__ 0 Motoredengine 262

-.20 _ 0 Motored engine 414

-,_0

-°

Exhaust

pressure,kPa

210

210531

-.4s I I I I I1400 1800 2200 2600 3000

Engine speed, rpm

Figure 52. - FMEPvalues versus engine speedfor hot firing engine.

g.,=*

t-I.a.

0 --

-2

-4

-6

-8

-10

-12

air pressure, "_pressure, kPa '_l

_ kPa '_I", 100 100 '_n 262 ZlO

_ 0 414 331 %

I I I I i l500 1000 1500 2000 2500 3000

Engine speed, rpm

Figure 53. - Friction powerequivalent for a motored engine opera-ting at three inlet air pressures.

o_

Fuel

quaplity,mm_/cycle

-4_-_ \\ A 1oo

__\\ _ _®_°

- \m,,

I I I '_

-6

-8

-10

-12

-14 I1400 1800 2200 2600 3000 3400

Engine speed, rpm

Figure 54. - Friction power for a hot firing engine operating under threeloads. Inlet air pressure, 2,52kPa; exhaust pressure, 210kPa.

z::l_

z:l.

o_

0 --

-5--

-10 --

-15 -

-20 --

-25

_/eo pri_re ' "_L_

[] 262 210 _ LJ'_ 414 331 X

\........ L __L___ J..... I I I

0 500 1000 1500 2000 2500 3000

Engine speed, rpm

Figure 55. - Motored friction powerplus pumpina Dowerversusengine speedfor three inlet air pressure.

:E

&

E-Ci-

-,I0 _ _

-. 20 -- Inlet Exhaus _''t _

- 25 -- air pressure, O_ 0

• pressure, kPa

kPa

IA 414 331

-.35 I 1 1 I I I500 1000 1500 2000 2500 3000

Engine speed, rpm

Figure 56. - PMEP values versus engine speed for motored engine

operating at three inlet air pressures.

c__

E

0 m

-2--

-4

_6 --

-8 --

-10 --

-120

F', PrID0

I I I I I I500 1000 1500 2000 2500 3000

Engine speed, rpm

Figure 57. - Pumping power losses versus engine speed for mo-

tored engine operating at three inlet air pressures.

.5

E o

-.5

-.I0

e_E

E

Fuel Inlet Exhaust Enginequantity, air pressure, operatingmm;Icycle pressure, kPa mode

kPa

---- -<> 0 i00 100-- ---_ 0 262 210 1 Motored--_ log ]

-- _ 120 } 262 210 Firing140 ]

-. |5 -- "- _G" ---. (:3

-.7o---I I L1400 1800 2200 2600

Engine speed, rpm30OO

Figure 58. -Comparison of PMEPfor an engine under mo-tored and under hot firing conditions.

-.1

8__E_- -.2

_:" -.3

kl

-.4

g

E -.5

u-,

o: -.6

-.7

Fuel Inlet Exhaust Enginequantity, air pressure, operating

mm>lcycle pressure, kPa modekPa

-----0 0 100 100 j

•-_ 0 262 210 f Motored--- --(i] 0 414 331

--_ 100 It_ 120 262 210 Firing

--t1_ 140

2-'.-.:o-, .<,,.

_

1 { I { I500 1000 1.500 2000 2500

Engine speed, rpm

Figure 59. - Combined FMEPand PMEPlosses from a motoredengine comparedwith operation of the engine under load.

I3OOO

(a) Brake specific fuel consimption, 218 g/kW-hr; inlet to exhaust pressure

ratio, 1.25.

(b) Brake specific fuel consimption, 208 g/kW-hr; inlet to exhaust pressure

ratio, 1.72.

(ct Brake specific fuel consimption, 203 g/kW-hr; inlet to exhaust pressure

ratio, 2. 40.

Figure _. - Pumping loop diagrams. Inte[air pressure, 262kPa; enginespeed, 2000 rpm; fuel quantity, 120 mm-'/cycle.

(a)Brakespecific fuel consumption, 213 g/kW-hr; inlet to exhaust pressure

ratio, 1.25.

tb) Brake specific fuel consumption, 195 g/kW-hr; inlet to exhaust pressureratio, 2.00.

(c) Brake specific fuel consimption, 188 g/kW-hr; inlet to exhaust pressureratio, 3.33.

Figure (}1. - Pumping loop diagrams. Inlet air pressure, 414 kPa; enginespeed, 2000 rpm; fuel quantity, 120 mm3/cycle.

.... I_EPu

I _Pu _p_AEP _u_

p_p •0 7"..... quanta,

_gu_ 62.-_lecto_e%_us_ b_su_e oo nne_netiec_.k_e

3.0

2.5

2.0

1.5

_ 1.0

"_ .5

E

E_ 3

_ 2v

-6 -4 -2 0 2 4 6

'(a) Engine speed,1500rpm.

).0 Fuelquantity,mm31cycle

2.5A I00 . f

v 13o .._ .,u0 160

2.0

1.0

.5-6 -4 -2 O 2 4

(b) Enginespeed,2500rpm.

l --

0-_

-j-12

J I ]-8 -4 0

2°5_

2.0--

1.5--

1.0

I I II4 8 Z2 "5-6 -4 -2 0 2 4

Encodermisalinement fromtop deadcenter, de9

(b) En9ine speed,2000rpm. tO)Enginespeed,30(]0rpm.

Figure 64. - Effects of encodermisalinement on net values of upperloopINEP. Inlet air pressure, 262 kPa; inlet-to-exhaustpressure ratio,1.25

I. Report No.

NASA TM- 86873

4. Title and SuD1itle

2. Government Accession No.

Baseline Performance and Emissions Data for a

Single-Cylinder, Direct-lnjected, Diesel Engine

7. Author(s)

Robert A. Dezelick, John J. McFadden, Lloyd W. Ream,

3. Recipient'l Catalog No.

5, Report Date

August 1984

6. Performing Orgsnizition Co0e

505-40-62

8. Performing Organization Report No,

10. Work Unit No.

E-207911. Contract or Grant No,

and Richard F. Barrows

g. Performing Organization Nlml and A0drets

National Aeronautics and Space Administration

Lewis Research Center

Cleveland, Ohio 44135

12.' Sponsoring Agency Name and Address

U.S. Department of Energy

Office of Vehicle and Engine R&D

Washington, D.C. 20585

13. Type of Report and Period Covered

Technical Memorandum

14. Sponsoring Agency-O_Jr Report No'.

DOE/NASA/501 94 -38

15. Supplementary Note=

Final Report. Prepared Under Interagency Agreement DE-A101-80CS50194.

1_ A_trimt

This report documents comprehensive fuel consumption, mean effective cylinderpressure, and emission test results for a supercharged, single-cylinder, direct-

injected, four-stroke-cycle, diesel test engine. Inlet air-to-exhaust pressureratios were varied from 1.25 to 3.35 in order to establish the potential effects

of turbocharging techniques on engine performance. Inlet air temperatures and

pressures were adjusted from 340 to 107 ° C and from 193 to 414 kPa to determine

the effects on engine performance and emissions. Engine output ranged from 300to 2100 kPa (brake mean effective pressure) in the speed range of 1000 to 3000

rpm. Gaseous and particulate emission rates were measured. Real-time values of

engine friction and pumping loop losses were measured independently and compared

with motored engine values.

17.Keywo.==(s.om.,.d by_mal_)

Diesel, Fuel consumption, Emissions,

Particulates, Turbocharged diesel,

Pumping loss, Turbocompound, Fuel injec-

tion, Friction loss

lg. Security Cl_mll. (of thle _ 20. Security Clumlf. (of thll page) 21. No. of page=

Uncl ass= fied Uncl ass= fied 29

J*For sale _ the National Technical Information Service, Springfield. Virginia 22161

18. Dlslrtbution Statement

Unclassified- Unlimited

Star Category 85

DOE Category UC-96

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