Engine Nacelle Halon Replacement

Point of Contact : Doug Ingerson

Department of TransportationFederal Aviation Administration

WJ Hughes Technical CenterFire Safety Branch, AAR-440

Bldg 205Atlantic City Int'l Airport, NJ 08405 USA

tel: 609-485-4945fax: 609-485-7074

email: [email protected] page: www.fire.tc.faa.gov

Federal Aviation Administration ~ WJ Hughes Technical CenterFire Safety Branch, AAR-440 ~ Atlantic City Int’l Airport, NJ 08405 USA

International Aircraft Systems Fire Protection Working GroupAtlantic City, NJ USA – 1-2November2005

Engine Nacelle Halon Replacement

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PRESENTATION CONTENTS

REVIEW EQUIVALENCE DATA TO DATE

DISCUSS PROGRESS REGARDING OBSERVED OVER-PRESSURES

DISCUSS STATUS

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REVIEWING EQUIVALENCE DATA TO DATE

AgentVentilation

configurationFire Threat

Equivalent Concentration (%v/v)

{FIXED DURATION/OBSOLETE

VALUES IN BRACES}

HFC-125

HighJP8 spray 17.5 {16.9}

JP8 pool 7.6 {9.6}

LowOIL spray 16.4 (a) {15.8}

JP8 pool 8.1 (a) {not determined}

CF3IHigh

JP8 spray 5.6 {5.8}

JP8 pool Incomplete

LowOIL spray 7.2 (a,b) {7.2}

JP8 pool Incomplete

(a) Bracketing method used to find mass equivalent

(b) Partial result, JP8 verification incomplete as of November 2005

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REVIEWING EQUIVALENCE DATA TO DATE

Agent FuelPeak, Critical or Design Concentration (%v/v)

REFERENCE

CF3I

PROPANE 6.5 (p) NFPA 2001, TABLE A-3-4.3

JP8 SPRAY 3.2 (c) NIST SP890, V.2, TBL 10, p.115

JP8 POOL 6.8 (c) NIST SP890, V.2, TBL 10, p.115

OIL 7.2 (d) FAATC; none; work in progress...

HFC-125

METHANE 14.7 (p) NFPA 2001, TABLE A-3-4.3

PROPANE 15.7 (p) NFPA 2001, TABLE A-3-4.3

PROPANE 12.6 (p) NIST SP890, V.2, FIG. 41, p.78

JP8 SPRAY 8.7 (c) NIST SP890, V.2, TBL 10, p.115

JP8 POOL 12 (c) NIST SP890, V.2, TBL 10, p.115

JP8 SPRAY, LoVent 25.4 (d) AFRL-VA-WP-TR-1999-3068

JP8 SPRAY, HiVent 18.2 (d) AFRL-VA-WP-TR-1999-3068

JP8 17.5 (d) FAATC; none; work in progress...

OTHER REPORTED or CALCULATED CONCENTRATIONS

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OVER-PRESSURE BEHAVIOR – BRIEF OVERVIEW

IN 2004, TWO HALON REPLACEMENT CANDIDATES WERE OBSERVED TO PRODUCE OVER-PRESSURE PHENOMENA SUBSEQUENT TO REIGNITION WITHIN THE TEST FIXTURE FLOW PATH 2-BTP HFC-125

HFC-125 & 2-BTP APPEARED TO ACT AS A FUEL IN SOME INSTANCES THE PHENOMENA WAS NOT 100% RELIABLE INVESTIGATION REQUIRED DUE TO FREQUENT OCCURRENCE

OUTCOMES 2-BTP WITHDRAWN FROM CONSIDERATION ENVIRONMENTAL BEHAVIORS FOR HFC-125 DURING OVER-

PRESSURE EVENTS WILL BE RECORDED IN NEAR-TERM TESTING TO PERMIT FUTURE DECISION-MAKING ACTIVITY

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OVER-PRESSURE BEHAVIOR – SCHEMATIC ORIENTATION

RETURN

SPRAY FIRE ZONE.

AGENT INJECTION

DUCT INTERFACE.

TEST SECTION EXIT = 22” DIA

EXHAUST DUCT ENTRANCE = 33” DIA

GAP BETWEEN CIRCULAR PLANES = 8”

~ 240 Inches

~ 123 Inches

~ 65 Inches

AIR FLOW

RED EXHAUST DUCT

TESTSECTION

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OVER-PRESSURE BEHAVIOR – DUCT INTERFACE IMAGE

DUCT INTERFACE.

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OVER-PRESSURE BEHAVIOR – ACTIVITIES/PLANS TO DATE

INSTRUMENTATION IS INSTALLED IN TEST FIXTURE & RED DUCT TO CAPTURE ENVIRONMENTAL BEHAVIORS DURING OVER-PRESSURE EVENTS 4 THERMOCOUPLES TO MONITOR TEMPERATURES IN RED DUCT 2 PRESSURE TRANSDUCERS TO RECORD STATIC PRESSURE 4 PHOTOCONDUCTIVE PHOTODIODES TO DETECT FLAME

DUCT INTERFACE CAN BE ISOLATED FROM TEST BAY MINIMIZED THE IMPACT ON THE VENTILATION STREAM ASSOCIATED

WITH DUCT INTERFACE ISOLATION PERFORMING ANALYTICAL EVALUATIONS OF THE DUCT INTERFACE

BERNOULLI VELOCITY MEASUREMENTS 1ST LAW OF THERMODYNAMICS

WILL RECORD ENVIRONMENTAL BEHAVIORS NEAR-TERM FIRE TESTING WITH NO AGENT, HALON 1301, & HFC-125 OIL & JP8 (??) SPRAY FIRES DUCT INTERFACE OPEN & CLOSED

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OVER-PRESSURE –TELEMETRY PLACEMENT

STA 502

THERMOCOUPLE

PHOTOCONDUCTIVEPHOTODIODE

STATIC PRESSURETRANSDUCER

THERMOCOUPLES SPACED EVERY2 FEET ALONG 12:00 & THE BEADS

ARE LOCATED 8 INCHES OFFTHE DUCT WALL

PHOTODIODES ORIENTED TO VIEW 12:00AT SPRAY FIRE ZONE, EXHAUST NOZZLE ENTRANCE,

EXHAUST NOZZLE EXIT, & RED DUCT

PRESSURE TRANSDUCERS RECORDSTATIC PRESSURE IN TEST SECTION

& THE RED DUCT

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OVER-PRESSURE –TELEMETRY BEHAVIORS/OPEN DUCT INTERFACE

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

Time (sec)Sta

tic

Pre

ssu

re(i

n H

2O)

0

1

2

3

4

5

6

7

Ph

otod

iod

e S

ign

alO

utp

ut

(VD

C)

static pressure, test section

static pressure, red duct

photodiode - tube array

photodiode - entrance exh nzl

photodiode - exit exh nzl

photodiode - red duct

NSe05811.xls, lfhs 05 811 13 c2

INLET TEMPERATURE = 90°F

BULK AIR TEMPERATURE = 250°F

D/I open, duct vents closed

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OVER-PRESSURE –TELEMETRY BEHAVIORS/CLOSED DUCT INTERFACE

-0.25

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

Time (sec)Sta

tic

Pre

ssu

re(i

n H

2O)

0

1

2

3

4

5

6

7

Ph

otod

iod

e S

ign

alO

utp

ut

(VD

C)

static pressure, test section

static pressure, red duct

photodiode - tube array

photodiode - entrance exh nzl

photodiode - exit exh nzl

photodiode - red duct

NSe05811.xls, lfhs 05 811 14 c2

INLET TEMPERATURE = 93°F

BULK AIR TEMPERATURE = 250°F

D/I closed, duct vents open to 512 in^2

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OVER-PRESSURE BEHAVIOR – ANALYTICAL EVALUATION

RECORD STATIC PRESSURE IN RED DUCT AT 2 LOCATIONS 21 INCHES FROM INLET & 7 INCHES OFF DUCT WALL (21/7) 16 INCHES FROM INLET & 4 INCHES OFF DUCT WALL (16/4) ALL FLOWS WERE THE SAME TEMPERATURE; NON-COMBUSTING

WORKED WITH STREAM LINES FROM TEST BAY INTO RED DUCT; SMOKE TRAIL OBSERVATIONS INDICATED : 21/7 WAS IN THE FLUCTUATION BETWEEN THE TEST BAY

EDUCTION FLOW & THE TEST SECTION EJECTA 16/4 WAS IN THE TEST BAY EDUCTION FLOW SOLELY

VELOCITIES (mass flows identified in parentheses are based on an assumption that speed is an average value for the annular surface area of the duct inlet where test bay air is entering; i.e. Q=AV; A=0.31 m^2) 21/7 :

T_bay= 13°C, V = 3 m/s (mdot 1.1 kg/s) T_bay= 26°C, V = 2.9 m/s (mdot 1.1 kg/s)

16/4 : T_bay= 26°C, V = 3.3 m/s (mdot 1.2 kg/s)

BERNOULLI VELOCITY ANALYSIS

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OVER-PRESSURE BEHAVIOR – ANALYTICAL EVALUATIONB

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CONTAINED DUCT INTERFACE WITHIN A CONTROL VOLUME (CV) NON-COMBUSTING FLOW CONDITIONS ESTIMATING MASS FLOW FROM THE TEST BAY INTO RED DUCT

THE PROBLEM IS UNDER-SPECIFIED THE CV WAS “MODELED” FOR VARIABLE INPUTS TO OBSERVE

BEHAVIOR OVER A RANGE OF CONDITIONS HEAT TRANSFER TO THE BAY ASSUMED NEGLIGIBLE WORK = 0 MASS FLOW FROM THE TEST SECTION IS REASONABLY SIMILAR

ACROSS THE AMBIENT CONDITIONS TO TREAT AS A CONSTANT VALUE (1 lbm/s +/- 0.1 lbm/s; 0.45 kg/s +/- 0.05 kg/s)

1ST LAW OF THERMODYNAMICS

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OVER-PRESSURE BEHAVIOR – ANALYTICAL EVALUATION1S

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red duct, inlet to exhaust

test section, exhaust nozzle

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NOZZLE EXHAUST

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OVER-PRESSURE BEHAVIOR – ANALYTICAL EVALUATION1S

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0

1

2

3

4

5

6

7

8

9

20 30 40 50 60 70 80 90 100 110 120 130

Bulk Air Temperature inRed Duct (°C)

Air

Mas

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low

En

teri

ng

Du

ct I

nte

rfac

e (k

g/s)

V_red = 3.5, V_bay / V_red = 0.8, adiabatic

V_red = 3.5, V_bay / V_red = 10, adiabatic

V_red = 3.5, V_bay / V_red = 0.8, Qdot = -3kw

V_red = 3.5, V_bay / V_red = 10, Qdot = -3kw

V_red = 7.0, V_bay / V_red = 0.8, adiabatic

V_red = 7.0, V_bay / V_red = 10, adiabatic

V_red = 7.0, V_bay / V_red = 0.8, Qdot = -3kw

V_red = 7.0, V_bay / V_red = 10, Qdot = -3kw

NS_thermodynamicanalysis.xls, different temps METRIC c

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TEST BAY = 29°C

JUMP TO TESTFIXTURE SCHEMATIC

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OVER-PRESSURE BEHAVIOR – SUMMATION TO DATE

TEST FIXTURE IS READY FOR TESTING IN OPEN & CLOSED DUCT INTEFACE CONFIGURATIONS

ANALYSIS OF VENTILATION AT DUCT INTERFACE NEARING COMPLETION SPEEDS FOR RED DUCT & TEST BAY FLOWS HAVE NEGLIGIBLE

IMPACT ON CALCULATIONS FOR TEST BAY MASS FLOWS ONLY WHEN AIR TEMPERATURE DIFFERS BETWEEN TEST

SECTION & TEST BAY NEGLIGIBLE IMPACT ILLUSTRATED BY CALCULATED CURVES

IN THE REASONABLE REGION OF BULK TEMPERATURE FOR THE RED DUCT FLOW (150-200°F/65-93°C)

THE GREATEST SENSITIVITY TO THE FLOW SPEEDS EXISTS WHEN THE 3 MASS FLOWS ARE THE SAME TEMPERATURE

ESTIMATING 1 kg/s OR LESS ENTERING RED DUCT FROM THE TEST BAY VIA THE INTERFACE

FUEL/AIR RATIOS TO BE CALCULATED

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CURRENT STATUS

NEED TO COMPLETE : HFC-125 OVER-PRESSURE CHARACTERIZATION

WORKING ON FUEL-AIR RATIO INFORMATION FOR JP8, OIL, & HYDRAULIC FLUID

TEST PLAN REQUIRES FINALIZATION CF3I EQUIVALENCE TESTING

JP8 POOL, HIGH & LOW VENTILATION JP8 SPRAY, LOW VENTILATION

COLD-SOAK HFC-125 PROOF (FIRE) TESTS

WRITE/PUBLISH REPORT & MPSE WILL CONSOLODATE WORDS FORMING MPSE & PASS AROUND TO

TASK GROUP FOR COMMENT MPSE TO BE APPENDIX MATERIAL IN FINAL REPORT REPORT BODY TO DESCRIBE HISTORY & LESSONS LEARNED DRAFT REPORT DUE SEP 2006

Documents

Engine Nacelle Halon Replacement