NOx and Soot Optimization using DI-Pulse Predictive Combustion … · 2015-08-20 · GT User Conference 2014, Bangalore Powertrain Engineering - Your Partner in Engine Design, Development

GT User Conference 2014, Bangalore Powertrain Engineering - Your Partner in Engine Design, Development & Testing . . .

Powertrain Engineering The Automotive Research Association of India,Pune

13th Oct 2014

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NOx and Soot Optimization using DI-Pulse Predictive Combustion Model

Authors H.B.Chaudhari N. H. Walke N. V. Marathe Dy Manager General Manager Sr Dy. Director, HoD, PTE


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• Introduction

• Application of 1D Thermodynamic Simulation

• Predictive combustion study

• Fuel injector 1D model

• Parametric study- DI pulse constants

• Sensitivity study- SOI, Prail, CR, pilot injection

• Summary


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ARAI is an Autonomous, Premier and self-supported R&D and Testing Institute; affiliated to Ministry of Heavy Industry, Govt of India; offering technical services in the area of design, development, testing and evaluation of vehicle and engines

Manpower strength 550*

Capital investment ~ 50 mn USD

10 Working Divisions - R&D : Power Train (Engine + Transmission), NVH, CAE, Automotive Electronics,

Structural Dynamics, Materials

Homologation : Emissions, Vehicle Evaluation, Safety, Component testing

Major Activities


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DIRECTOR

SPECIAL PROJECTS

INFRASTRUCTURE DEVELOPMENT

BUSINESS DEV. & CORP. PLANNING

HOMOLOGATION

HR MANAGEMENT

R&D-1 VEHICLE SYSTEMS

R&D – 2 POWER TRAIN &

ELECTRONICS N

VH

STR

UC

TUR

AL

DY

NA

MIC

S

VEH

ICLE

D

YN

AM

ICS

CA

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EMIS

SIO

NS

V

EHIC

LE

EVA

LUA

TIO

N

SAFE

TY

CO

MP

ON

ENTS

/ S

YST

EMS

EN

GIN

ES &

TR

AN

SMIS

SIO

N

AU

TOM

OTI

VE

ELE

CTR

ON

ICS

FINANCE & ACCOUNTS

SECRETARIAL & LEGAL

ACADEMY

HO

MO

LOG

ATI

ON

MG

MT

& R

EGU

LATI

ON

Secretariat

Governing Council Auto Industry representation

Government of India representation

Organization Structure of ARAI


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Design and Simulation Tools at Power Train Engineering

EXCITE DESIGNER GT Suite (crank,

valve train) TYCON

GLIDE

BOLT

FIRE STAR CCM+

BOOST GT Suite

CRUISE

Auto-CAD

PRO-E

NASTRAN

GT Suite

FLOWMASTER

HYDSIM

ROMAX DESIGNER

ANSYS SYSNOISE ADAMS

FE-FATIGUE LMS-DYNA

ABAQUS FLUENT

CA

E d

ivis

ion

PT

E

PT

E

PT

E

PT

E

PTE developed

softwares

Valve train TV analysis Oil pump Water pump

PT

E


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Goal of Simulation

Moving from Lab and field testing to desktop- Virtual analysis !!!

Analytical study for process understanding

Predictive study- design tool

Parameter optimization


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1D Thermodynamic simulation

Simple physics, fast execution Complete engine system design Zero-D combustion models for analytical studies Multizone combustion models for performance

and emission trends

3D CFD combustion simulation

Complicated physics, high time and cost

Selective component analysis

Detailed combustion models for accurate prediction of emissions

Simulation Approach


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• Introduction






• Summary


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Hardware selection for Prototype

TC, EGR system

Valve timings

Manifold dimensions, intake/exhaust routing

Combustion system


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Air handling Turbocharger matching EGR system design

Gas exchange Valve timing analysis Manifold tuning

In-cylinder combustion Engine performance Emission trends

Heat balance Engine heat balance

analysis Heat flux, heat

transfer coefficients

1D thermodynamic model

Validation and sensitivity analysis

Post processing

Modifications

Predictive study

Optimum results

Verification

FTP, part load test data Engine performance

TC matching

NA to TC New emission norms

Performance improvement

recalibration

i/p changes

calibration

improvements

Geometrical data Port flow coefficients

Valve timings Valve lift profiles

Gas exchange Heat balance Air handling

Combustion trends Emission trends

CR, valve timings, TC, SOI, TC h/w, EGR system,

Manifold

Proto engine testing

Applications of 1D tool

Steps to carry out 1D simulation


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Turbocharger Matching

Calculation of operating points TC proposal from supplier along with maps Checking the quality of maps for better confidence Checking the Compressor & Turbine suitability Altitude study, high ambient temperature study


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Gas Exchange-Valve timing analysis

Exhaust Valve Opening (EVO)

Influence on fuel consumption

Speed dependent optimum EVO value

Influence of blow down during valve overlap period


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Heat balance analysis

Inputs Outputs


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Heat balance analysis

Use of 1D boundary conditions like heat flux/htc for 3D CHT analysis


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Non predictive-Combustion Pressure Analysis

Measured in-cylinder pressure ROHR analysis PV analysis

Inputs Outputs

Generated combustion profile can be used for analytical study


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Predictive-Injection rate modeling

Inputs Calibration Outputs

Predictive calibrated combustion model gives accurate trends of Nox emissions

Nox trends


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• Introduction






• Summary


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Predictive combustion study- DI pulse model

1D thermodynamic model

Validation and sensitivity analysis

Post processing

Modifications

Predictive study

Optimum results

Verification

Goal

to find the single set of model constants

to provide the best possible match to a wide variety of operating points


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Predictive combustion study- DI pulse model

Requirement Injection profiles

In-cylinder pressure at speed

load sweep


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Engine 1D Thermodynamic Model

Engine specifications • TCIC common rail off road • 2 valve/ cylinder • Rated bmep ~14 bar • Torque backup ~25% • Stringent emission & bsfc

targets

Engine design from scratch !!


DI pulse parameters Min Max

Entrainment Rate

Multiplier

0.5 2.8

Ignition Delay Multiplier 0.3 1.7

Premixed Combustion

Rate Multiplier

0.05 2.5

Diffusion Combustion

Rate Multiplier

0.4 1.4

Input data required for DI-pulse calibration • Cylinder pressure • Volumetric efficiency • Residual fraction • Trapping Ratio • Injection profile • Fuel injection parameters

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Predictive Combustion Modeling (DI PULSE)


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• Introduction






• Summary


Modeling of Fuel Injector

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Typical injector model Required for generating injection rate curves at various operating points



Typical input profile for the solenoid injector

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Simulated injection characteristics at 1600bar rail pressure and energizing time of 4ms

Simulated injection rates at 2000 bar rail pressure After profile conditioning

Design of experiments is carried out to calculate injection rates for multiple rail pressures and injector energizing times • Rail Pressure from 400 bar to 2000 bar with 200 bar increment • Energising time varied from 0.5 milliseconds to 1.75 milliseconds with 0.05 increment

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Predicted Energizing-Time map from 1D injector model


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• Introduction






• Summary


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Effect of DI pulse constants on combustion- Entrainment


Entrainment Rate Multiplier 0.5 2.8

Ignition Delay Multiplier 0.508

Premixed Combustion Rate Multiplier 1.481

Diffusion Combustion Rate Multiplier 0.81

min


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Effect of DI pulse constants on combustion- Ignition Delay


Entrainment Rate Multiplier 1.033

Ignition Delay Multiplier 0.3 1.7




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Effect of DI pulse constants on combustion- Premixed




Premixed Combustion Rate Multiplier 0.05 2.5



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Effect of DI pulse constants on combustion- Diffusion





Diffusion Combustion Rate Multiplier 0.4 1.4

min


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Rail Pressure (bar) 1600

Injection Timing At TDC

Injected mass (Main Injection mg) 60 Residual Fraction at IVC (including

EGR) 20.1

Calibration -Predictive Combustion Modeling (DI PULSE)

Expt

Sim


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Calibration -Predictive Combustion Modeling (DI PULSE)

Calibrated Dipulse constants

Entrainment 1.033

Ignition Delay 0.508

Premixed 1.481

Diffusion 0.810

Variation ~ +/-15%

-60 -40 -20 0 20 40 60

In-c

ylin

der

pre

ssu

re (

bar

)

Crank Angle (deg)

Incylinder Pressure at Intermediate speed

-60 -40 -20 0 20 40 60

In-c

ylin

der

pre

ssu

re (

bar

)

Crank Angle (deg)

Incylinder Pressure at rated speed


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• Introduction






• Summary


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Sensitivity analysis-Start of injection Rated speed, 100 % load

advance advance

advance


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Sensitivity analysis-Start of injection Intermediate speed, 100 % load

retard retard

retard


Sensitivity analysis- injection pressure Rated speed, 100 % load

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Sensitivity analysis- injection pressure Intermediate speed, 100 % load

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Prail (bar)

Prail (bar)


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Sensitivity analysis- EGR rate

Validated case


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Sensitivity analysis- Pilot injection

Effect on NOx

1 2 main 1 main


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Parametric study- CR, SoI Rated speed, 100 % load


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• Introduction






• Summary


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Summary Methodology for the predictive combustion model- DI pulse calibration has been

discussed

The model responds reliably to varying in-cylinder conditions like, Start of injection injection pressure EGR rate pilot injection

The NOx and soots are following the trends with respect to test data

The model can be further used for

Multiple injection strategy Transient simulations


Thank You !

Prepared by H.B.Chaudhari Dy Manager Simulation, PTE [email protected] +91 2030231469/1308

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Acknowledgement The authors would like to thank Mr Sanjeev Gothekar, Dy. Manager, for providing experimental data required for carrying out validation and calibration work. Also we would like to appreciate exhaustive work done by Mr Nijesh N. Mtech student, in carrying out injector modeling and post processing of data.

mailto:[email protected]

Documents

NOx and Soot Optimization using DI-Pulse Predictive Combustion … · 2015-08-20 · GT User Conference 2014, Bangalore Powertrain Engineering - Your Partner in Engine Design, Development