Nov. 2003 SCS/SYS/N/17/3737_01.DOC Fuel Tank Inerting Joint Airbus/FAA, A320 Flight Tests Presented by Dr. Ali Tehrani Systems Fire Protection Group Meeting

SCS/SYS/N/17/3737_01.DOC

Nov. 2003

Fuel Tank Inerting

Joint Airbus/FAA, A320 Flight Tests

Presented by

Dr. Ali Tehrani

Systems Fire Protection Group MeetingAtlantic City, New JerseyNov. 2003

Nov. 2003 SCS/SYS/N/17/3737_01.DOC Page 2

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Aims and Objectives

The main objectives of the flight test are to:

• Demonstrate supply of inert gas to the centre tank, throughout the flight profile, using the FAA prototype system,

• Assess the centre tank gas distribution over different flight phases,

• Validate the in-tank gas distribution (O2 concentration) measured with those numerically modelled,

• Assess performance of a typical ASM operating during different flight phases.


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Test Installation

• The source of Nitrogen Enriched Air (NEA) was obtained using equipment loaned from the FAA,

Equipment was located in the cargo bay on an LD3 pallet.• Bleed air provided by tapping into bleed air duct,• NEA was introduced into the centre tank using a pipe normally used for ACT

fuel transfer when ACT is fitted,• The outlet housing configuration of the transfer pipe in the centre tank was

used to incorporate a NEA discharge nozzle,• Oxygen concentration in the centre tank was measured using the FAA

sampling system OBUSS, This allowed measurement of oxygen concentration from 8

locations in the tank,• Additional measurements of temperature and pressure were made in the

centre tank and on the NEA generating equipment,• Cooling air was supplied from the cargo bay environment,• OEA (Oxygen Enriched Air) was discharged over board using existing drain

mast.


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Outline of OBIGGS Equipment and Interfaces

Bleed Line

Temp control valve, cabin controlled

Heat Exchanger

Filter

ASMs

Shut Off Valve

Heater

High and Low Flow Valves(In common valve)

Centre Tank

Waste Flow (O2 rich)

Check Valves

Discharge Line

NEA Flow

Bleed Air Isolation, controlled via cockpit

Bleed Interface

Cooling Inlet Interface

Cooling outlet Interface

NEA Supply Interface

FAA PALLET

Waste Flow Interface

Cooling AirIsolation Valve

Fan

Bypass Valvewith pressure supply bottle

Outside Aircraft

Outflow Valve

NEA Injection Line


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OBIGGS as installed on Pallet


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Centre Tank Oxygen Sensor Location

Probe 1

Probe 3

Probe 4

Probe 2

Probe 5Probe 6

Probe 7 Probe 8


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O2 Measurement Locations in Centre Tank


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Ground and Flight Testing

• Ground testing of the system included a period of 50 hours “mini-endurance” tests to gain confidence in the system operation.

• The flight testing phase included a number of 9 flights, exploring system performance over a range of;

Tank fuel quantitiesClimb and descent ratesDifferent OBIGGS operational configuration

• Total flight test time was approximately 20 hours.


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Flight Test Data – Oxygen Concentration

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

10 25 40 55 70 85 100 115

Time (min)

Alt

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(ft

)

0

5

10

15

20

25

O2

Vo

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e F

rac

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%)

Altitude

Location 1

Location 2

Location 3

Location 4

Location 5

Location 6

Location 7

Location 8


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CFD results and Data Points, Ground Operation, Adjacent to Vent Inlet


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CFD Results and Data points, Ground operation, Tank Average


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Comparisons of Modelling and Data points – Tank Average

Measured Data

Predicted results

Time (Min.)

Oxy

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Simulation of Ground Test (CFD)


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Conclusion

• No major abnormal system operation was observed during different phases of the ground and flight test,

• Variation in supply pressure appeared to have a dominating effect on the overall system performance,

• Reasonably uniform O2 concentration observed within the tank during the climb and cruise,

• Good agreement with numerical prediction of the gas distributions for steady states and flight phases.

• Normal servicing of the aircraft was not hindered, but the maintenance crew were briefed on the operations associated with the potential hazards of nitrogen rich atmosphere.

• Time taken to return tank to all air environment was approx. 30 Mins.


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Lessons Learnt

• Thermal characteristic of the ASM needs further investigation.• Impact on reaching the optimum operating temperature• Operated in a conditioned cargo hold only investigated.

• A variable flow system may offer some advantages,

• Initial purging of the tank may impose additional ASM requirements post maintenance,

• Function of the filter needs further investigation.• The filter used was oversized for this application.

The FRS concept proposed by the FAA was demonstrated to operate during the limited flight trials.

However, significant development is still required for a fully commercial

operational system.


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This document and all information contained herein is the sole property of AIRBUS UK LTD. No intellectual property rights are granted by the delivery of this document or the disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of AIRBUS UK LTD. This document and its content shall not be used for any purpose other than that for which it is supplied.

The statements made herein do not constitute an offer. They are based on the mentioned assumptions and are expressed in good faith. Where the supporting grounds for these statements are not shown, AIRBUS UK LTD will be pleased to explain the basis thereof.

Documents

Nov. 2003 SCS/SYS/N/17/3737_01.DOC Fuel Tank Inerting Joint Airbus/FAA, A320 Flight Tests Presented by Dr. Ali Tehrani Systems Fire Protection Group Meeting