Engine Nacelle Halon Replacement

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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
Agent Ventilation configuration Fire Threat Equivalent Concentration (v/v) FIXED DURATION/OBSOLETE VALUES IN BRACES
HFC-125 High JP8 spray 17.5 16.9
HFC-125 High JP8 pool 7.6 9.6
HFC-125 Low OIL spray 16.4 (a) 15.8
HFC-125 Low JP8 pool 8.1 (a) not determined
CF3I High JP8 spray 5.6 5.8
CF3I High JP8 pool Incomplete
CF3I Low OIL spray 7.2 (a,b) 7.2
CF3I Low JP8 pool Incomplete
(a) Bracketing method used to find mass equivalent (a) Bracketing method used to find mass equivalent (a) Bracketing method used to find mass equivalent (a) Bracketing method used to find mass equivalent
(b) Partial result, JP8 verification incomplete as of November 2005 (b) Partial result, JP8 verification incomplete as of November 2005 (b) Partial result, JP8 verification incomplete as of November 2005 (b) Partial result, JP8 verification incomplete as of November 2005
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REVIEWING EQUIVALENCE DATA TO DATE
OTHER REPORTED or CALCULATED CONCENTRATIONS
Agent Fuel Peak, Critical or Design Concentration (v/v) REFERENCE
CF3I PROPANE 6.5 (p) NFPA 2001, TABLE A-3-4.3
CF3I JP8 SPRAY 3.2 (c) NIST SP890, V.2, TBL 10, p.115
CF3I JP8 POOL 6.8 (c) NIST SP890, V.2, TBL 10, p.115
CF3I OIL 7.2 (d) FAATC none work in progress...
HFC-125 METHANE 14.7 (p) NFPA 2001, TABLE A-3-4.3
HFC-125 PROPANE 15.7 (p) NFPA 2001, TABLE A-3-4.3
HFC-125 PROPANE ?12.6 (p) NIST SP890, V.2, FIG. 41, p.78
HFC-125 JP8 SPRAY 8.7 (c) NIST SP890, V.2, TBL 10, p.115
HFC-125 JP8 POOL 12 (c) NIST SP890, V.2, TBL 10, p.115
HFC-125 JP8 SPRAY, LoVent 25.4 (d) AFRL-VA-WP-TR-1999-3068
HFC-125 JP8 SPRAY, HiVent 18.2 (d) AFRL-VA-WP-TR-1999-3068
HFC-125 JP8 17.5 (d) FAATC none work in progress...
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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
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OVER-PRESSURE BEHAVIOR DUCT INTERFACE IMAGE
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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
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OVER-PRESSURE TELEMETRY BEHAVIORS/OPEN DUCT
INTERFACE
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OVER-PRESSURE TELEMETRY BEHAVIORS/CLOSED DUCT
INTERFACE
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OVER-PRESSURE BEHAVIOR ANALYTICAL EVALUATION
BERNOULLI VELOCITY ANALYSIS

• 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.
  QAV A0.31 m2)
• 21/7
• T_bay 13C, V 3 m/s (mdot ? 1.1 kg/s)
• T_bay 26C, V 2.9 m/s (mdot ? 1.1 kg/s)
• 16/4 T_bay 26C, V 3.3 m/s (mdot ? 1.2 kg/s)

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OVER-PRESSURE BEHAVIOR ANALYTICAL EVALUATION
BERNOULLI VELOCITY ANALYSIS
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OVER-PRESSURE BEHAVIOR ANALYTICAL EVALUATION
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OVER-PRESSURE BEHAVIOR ANALYTICAL EVALUATION
1ST LAW OF THERMODYNAMICS

• 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)

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OVER-PRESSURE BEHAVIOR ANALYTICAL EVALUATION
1ST LAW OF THERMODYNAMICS
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OVER-PRESSURE BEHAVIOR ANALYTICAL EVALUATION
1ST LAW OF THERMODYNAMICS
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OVER-PRESSURE BEHAVIOR ANALYTICAL EVALUATION
JUMP TO TEST FIXTURE SCHEMATIC
1ST LAW OF THERMODYNAMICS
TEST BAY 29C
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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
  (150-200F/65-93C)
• 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