1D Modelling of Thermal Management of a Jet Trainer
Aircraft 2023-01-1005
Most of current jet aircraft circulate fuel on the airframe to match heat loads
with available heat sink. The demands for thermal management in wide range of
air vehicle systems are growing rapidly along with the increased mission power,
vehicle survivability, flight speeds, and so on. With improved aircraft
performance and growth of heat load created by Aircraft Mounted Accessory Drive
(AMAD) system and hydraulic system, effectively removing the large amount of
heat load on the aircraft is gaining crucial importance. Fuel is becoming heat
transfer fluid of choice for aircraft thermal management since it offers
improved heat transfer characteristics and offers fewer system penalties than
air. In the scope of this paper, an AMESim model is built which includes
airframe fuel and hydraulic systems with AMAD gearbox of a jet trainer aircraft.
The integrated model will be evaluated for thermal performance. JP-8 fuel is
recirculated on the airframe to maintain cooling the oil for AMAD gearbox and
the hydraulic fluid for the hydraulic systems. A Fuel/Oil Heat Exchanger (FOHE)
is integrated on the airframe main fuel line with a thermally actuated valve
located at the fuel outlet port, which prevents fuel temperature from exceeding
limitations at the airframe/engine fuel interface. The valve opens at a
specified fuel temperature allowing excessive fuel to return to main fuel tank
that increase fuel flow through the heat exchanger. AMAD and hydraulic systems
also have their own thermal by-pass valves to adjust fluid quantity to be sent
to the heat exchanger for cooling.