BRIEF OVER VIEW OF THE MINIMUM PERFORMANCE STANDARD FOR ENGINES

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• BRIEF OVER VIEW OF THE MINIMUM PERFORMANCE
  STANDARD FOR ENGINES
• describes geometry for a fixture loosely
  representing an aircraft engine nacelle
• describes process to produce a representation of
  the current level of safety protecting these
  spaces
• puts halon through an obstacle course looking
  for a specified performance
• upon achieving the specified performance, pull
  out the halon and iterate to a quantity of a
  replacement repeating the same performance as
  halon
• quantify replacement
• DISCUSSED SIMULATOR CONFIGURATION AND PROVIDED
  CURRENT SIMULATOR STATUS
• provided schematic view of the simulator
• discussed hot plates plate heating configuration
  resolved, still need to get plate into the core
  section
• discussed heating the air flow stream will do it
  in 2 steps, one heat addition at the inlet and
  second heat addition from the heated surface of
  the simulator core
• presented curve characterizing flow capacity of
  simulator _at_65F, range of 2-11 lbm/s and 15-80
  compartment changes per minute
• 1-2 months remain to completion
• DISCUSSED HALONYZER DISCREPANCIES
• fire testing in 1998 indicated fire test data
  timeline did not correlate with Halonyzer II
  timeline for distribution
• performed in-house testing to evaluate nature and
  magnitude of discrepancy
• determined the key discrepant factor was the
  transport of the sample through the sampling
  probe (tube to transport sample from the sample
  point to the transducer)
• resulted in selecting a smaller probe

Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422
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Dimensions of Various Cross Section for the
Nacelle Simulator Ro or H Ri or
W area area comment in in in2 ft2 A - - - -
transition duct B 11 0 380 2.64 exhaust nozzle
cross section C 17.5 0 962 6.68 exhaust nozzle
cross section D 24 12 1357 9.42 test section aft
end F 24 12 1357 9.42 test section
middle G 24 12 1357 9.42 test section
inlet H 21 6.51 1252 8.69 inlet diffuser
middle J 18 1.02 1016 7.06 inlet diffuser
entrance K 18 0 1018 7.07 approach
duct L 18 0 1018 7.07 straightening
grill M 18 0 1018 7.07 straightening grill
entrance N 35 35 1225 8.51 tube bank heat
exchanger shell P 18 0 1018 7.07 transition
duct Q 24 17.5 420 2.92 blower
outlet R - - - - supply blower, 3 hp, 22" dia.
inlet
Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422

• Nacelle Simulator Status
• Working on heating the core surface
• Need to mount hot plates
• Need to install two duct heaters at inlet

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High Bypass Ratio Turbofan Nacelle Simulator
Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422
4
High Bypass Ratio Turbofan Nacelle Simulator
Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422
5
High Bypass Ratio Turbofan Nacelle Simulator
Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422
6
High Bypass Ratio Turbofan Nacelle Simulator
Comparing Analyzer Response for 5 V/V Halon
1301, Varying Probes
Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422
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High Bypass Ratio Turbofan Nacelle Simulator

• Given the compartment ventilation rate
  (changes/min) in the nacelle is related to that
  of the analyzer probe.
• Variables given are describing
• Q volumetric flow rate
• V internal volume of probe or nacelle
• A internal cross sectional area of probe or
  nacelle
• L length of probe or nacelle
• x dot average gas flow velocity in probe or
  nacelle
• f factor relating the two air change rates
• subscript E, related to engine nacelle
• subscript T, related to analyzer probe (tube)
• Formulation illustrates air change rates are
  dependent upon ratios of (neglecting complex
  flow interactions)
• lengths of the probe and nacelle
• gas stream velocities
• For true real-time history, the transducer must
  see the gas flow at the same velocity the nacelle
  sees the factor of f LE / LT must approach
  1.
• One can treat the nacelle event as a source (as
  in source/sink relationships) because the total
  sampling volume from the nacelle flow is
  negligible the factor f LE / LT can be set
  to approach zero therefore capturing the event
  with inconsequential time dilation considerations.

Gas Concentration Data Disagreement with Fire
Test Data
Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422
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High Bypass Ratio Turbofan Nacelle Simulator
The trace from the 1/8ODx20 ft long probe is
approximately a pure time displacement of the
near-square wave forms shown.
Douglas Ingerson Federal Aviation
Administration W.J. Hughes Technical
Center Atlantic City Intl Airport, NJ Fire
Safety section, AAR-422
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High Bypass Ratio Turbofan Nacelle Simulator
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High Bypass Ratio Turbofan Nacelle Simulator
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High Bypass Ratio Turbofan Nacelle Simulator
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High Bypass Ratio Turbofan Nacelle Simulator
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High Bypass Ratio Turbofan Nacelle Simulator

• Halon 1301 curves are translated along the time
  axis for clarity.
• the agent weights transferred to the fire
  extinguisher was not in accordance with the
  procedure to correctly simulate Halon 1301 with
  HFC-125.
• Generally agreeable qualitative behavior is still
  observed