Application of a Body Force Approach for Numerical Heat Exchanger Simulations within a Hybrid Electric Propulsion Aircraft Concept

Abstract

Hybrid electric propulsion concepts have a great potential to reduce the overall emissions of aviation. For fuel cell applications heat exchangers are required to dissipate the waste heat produced by the fuel cell. The integration of the heat exchangers has an impact on the aircraft aerodynamics which in turn is influencing the flow through the cooler duct. This paper presents a new approach in the DLR TAU Code to model a heat exchanger using the body force method in the Flowsimulator framework. The results are verified using analytic solutions and OpenFoam simulations. The results indicate that the approach is robust and properly resolving the underlying physics. The comparison between the analytic solution and the new heat exchanger model is very good. Fine grid resolutions are necessary to resolve the flow through the cooler properly. First applications for the new method are shown for a fuselage-mounted cooler as well as for a nacelle-mounted cooler.