# Presentation: 334745

## 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; @65°F, 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
- correction closely matches a near-square wave trace with a twenty foot long probe trace
- DISCUSSED HFC-125 SIMULATION OF HALON 1301 DISTRIBUTION
- showed April 1998 test data
- showed recent simulator test pairing; concentration magnitudes discrepant
- attribute discrepancy to inconsistent weight measurements on the scale used to determine agent quantities
- additional work during simulator distribution set up is planned
- technical note is in editorial review soon to be published

- Douglas Ingerson
- Federal Aviation Administration
- W.J. Hughes Technical Center
- Atlantic City Int’l Airport, NJ
- Fire Safety section, AAR-422

## Dimensions of Various Cross Section for the Nacelle Simulator

- 	Ro or H	Ri or W	area	area	comment
- 	in	in	in^2	ft^2
- 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 Int’l 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

## High Bypass Ratio Turbofan Nacelle Simulator

- Douglas Ingerson
- Federal Aviation Administration
- W.J. Hughes Technical Center
- Atlantic City Int’l Airport, NJ
- Fire Safety section, AAR-422

## High Bypass Ratio Turbofan Nacelle Simulator

- Douglas Ingerson
- Federal Aviation Administration
- W.J. Hughes Technical Center
- Atlantic City Int’l Airport, NJ
- Fire Safety section, AAR-422

## High Bypass Ratio Turbofan Nacelle Simulator

- Douglas Ingerson
- Federal Aviation Administration
- W.J. Hughes Technical Center
- Atlantic City Int’l Airport, NJ
- Fire Safety section, AAR-422

## High Bypass Ratio Turbofan Nacelle Simulator

**High Bypass Ratio Turbofan Nacelle Simulator**

- Douglas Ingerson
- Federal Aviation Administration
- W.J. Hughes Technical Center
- Atlantic City Int’l Airport, NJ
- Fire Safety section, AAR-422

**Comparing Analyzer Response for**
**5% V/V Halon 1301, Varying Probes**

## High Bypass Ratio Turbofan Nacelle Simulator

- Douglas Ingerson
- Federal Aviation Administration
- W.J. Hughes Technical Center
- Atlantic City Int’l Airport, NJ
- Fire Safety section, AAR-422

- 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 * [L****E**** / L****T****]}** 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 * [L****E**** / L****T****]}** can be set to approach zero; therefore capturing the event with inconsequential time dilation considerations.

**Gas Concentration Data Disagreement with Fire Test Data**

## High Bypass Ratio Turbofan Nacelle Simulator

- Douglas Ingerson
- Federal Aviation Administration
- W.J. Hughes Technical Center
- Atlantic City Int’l Airport, NJ
- Fire Safety section, AAR-422

- The trace from the 1/8”ODx20 ft long probe is approximately a pure time displacement of the near-square wave forms shown.

## High Bypass Ratio Turbofan Nacelle Simulator

## High Bypass Ratio Turbofan Nacelle Simulator

## High Bypass Ratio Turbofan Nacelle Simulator

## High Bypass Ratio Turbofan Nacelle Simulator

## High Bypass Ratio Turbofan Nacelle Simulator

**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