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Thermal sensitivity analysis of avionic and environmental control subsystems to variations in flight condition

conference contribution
posted on 28.01.2016, 10:15 authored by Andy Jones, Thomas Childs, Rui Chen, Angus Murray
The operation of fast jet military aircraft spans a large flight and atmospheric envelope. This study is the analysis of an avionic thermal management system for a typical fast jet military aircraft across changing operating conditions. The system which governs avionic module temperature is only partially active; therefore the efficiency and heat rejection capability is almost completely dependent on the system inputs of flight and atmospheric conditions. The thermal sensitivity to variation in system inputs is assessed with the use of experimental testing, one-dimensional thermodynamic modelling and energy flow calculations. The avionic module is the final component of the thermal management flow path and to understand the performance at component level, every subsystem upstream must be considered through a complete systemic approach. The facility used to deliver this analysis considers the total system energy consumption, Environmental Control System (ECS), cabin and three avionic subsystems as a single airflow path. The system is subjected to a typical fast jet flight profile, including a take-off, climb, cruise, combat, landing and ground operation cases. The flight profile is considered across three atmospheric conditions; ISA standard, hot and cold. It is found that the system heat rejection is stable with variations in flight conditions; therefore the system efficiency is inversely proportion to total energy consumption. The highest system efficiency is delivered at high altitude low load cruise conditions, with the lowest efficiency found at high speed low attitude flight. The system is most efficient when thermal safety factor is lowest. This is hot atmospheric and low load conditions, where the ECS bypass flow rate is low and avionic module exhaust temperatures are high. The ground ops condition in a hot atmosphere is the worst case scenario for avionic module exhaust and cabin temperatures. Considerable system gains could be made by introducing an element of active control, such as limiting bleed and ram air consumption when avionic temperatures are low and ECS bypass flow rate is high.

Funding

The project is co-funded by EPSRC (Engineering and Physical Sciences Research Council, UK), Loughborough University and BAE Systems.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Aeronautical and Automotive Engineering

Published in

AIAA SciTech, 54th AIAA Aerospace Sciences Meeting

Volume

AIAA 2016-1980

Citation

JONES, A. ...et al., 2016. Thermal sensitivity analysis of avionic and environmental control subsystems to variations in flight condition. Presented at: 54th AIAA Aerospace Sciences Meeting, AIAA SciTech, San Diego, USA, AIAA 2016-1980

Publisher

American Institute of Aeronautics and Astronautics

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2016

Notes

This paper is in closed access.

Language

en

Location

San Diego, California, USA

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