Tank Heating Model for Aircraft Fuel Thermal Systems with Recirculation

Fuel thermal management is an important consideration in the design and operation of modern high performance aircraft. In many cases, fuel is a primary heat sink for thermal loads associated with the cooling of the airframe as well as propulsion, electronic, actuator, and payload systems. It is now common for thermal systems to recirculate warm fuel to the tanks, resulting in a rise in temperature of the mission fuel mass. This paper presents a model that integrates heat transfer during mission segments to determine the thermal endurance of an aircraft in terms of fuel tank temperature rise. Cases with and without tank-wall heat transfer are considered. The model is intended for early-phase trade studies to determine whether a proposed vehicle design will likely be restricted in operational performance by tank temperature limits. An example is provided to demonstrate the application of the model to determine tank temperature rise during a notional aircraft mission.