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Overall Aircraft System-of-Systems Thermal Model and Simulation Tool


TECHNOLOGY AREA(S): Air Platform, Ground Sea, Electronics 

OBJECTIVE: Design and develop a model and simulation (M&S) tool to establish the overall aircraft system-of-systems (SoS) thermal management to determine the least efficient sub-system so that improvements can be made to increase the overall aircraft energy efficiency. 

DESCRIPTION: The aircraft is a SoS that presently is not well defined with respect to overall thermal management, with only the individual systems defined including their size and weight. The Navy seeks a tool that can accurately model the overall thermal management of the aircraft SoS, including all individual sub-systems (i.e., fuel, engine, Aircraft Mounted Accessory Drive (AMAD), electrical, avionics, sub-systems, fuel/air energy processes), to determine where improvements can be made to overall efficiency. This model would be used to assess and quantify failure modes on the aircraft when changes/improvements are made to individual sub-systems for present and future aircraft upgrades. Avionics upgrades increase generator electrical load, which increases the heat to the generator cooling oil. The cooling oil increases heat transfers to an oil/fuel heat exchanger to the fuel. Additionally, the radar upgrades would increase heat that goes through a Polyalphaolefin Liquid to the fuel heat exchanger. Any engine upgrades may also increase the engine heat that transfers through the engine oil to the fuel. The increased heat to the fuel can coke the engine. The tool should be developed using the known thermal aircraft predicted loads that are defined in the thermal load analysis. The model would use predicted heat loads (kilo-watts) and calculate the resultant temperature data. The calculated temperatures will be compared to aircraft temperature data archived by Boeing to test the model’s validity. Fighter aircraft temperature data and thermal load analysis will be provided by the Government. As upgrades occur, the software would be used to predict thermal increases. The tool should have the ability to import data from Microsoft Excel. 

PHASE I: Define and develop an approach for a modeling and simulation tool able to analyze existing fighter aircraft heat loads using data to be provided by the Government. Ensure that the model approach is capable of adding future heat loads that result from an aircraft upgrade. The Phase I effort will include prototype plans to be developed under Phase II. 

PHASE II: Develop and demonstrate prototype software modeling and simulation tool for an aircraft system. Validate the software using Government-furnished thermal and temperature data. 

PHASE III: Develop and demonstrate a platform-specific thermal management system modeling tool using temperature data. Transition the tool to appropriate program offices. Commercial aircraft and automotive manufacturers can benefit from using the model to determine the thermal impact on cooling systems. 


1. Ahlers, Mark. “Aircraft Thermal Management: Systems Architectures.” . SAE International, April 30, 2016; ISBN-10: 076808296X; ISBN-13: 978-0768082968.; 2. Sundén, Bengt and Fu, Juan. “Heat Transfer in Aerospace Applications.” Academic Press, 2017; ISBN 978-0-12-809760-1.

KEYWORDS: Thermal; Integration; Fuel; Electrical; Oil; Analysis 

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