Development of Heat Exchanger Modeling Capability for a Finite-Volume Aeroelasticity Solver

Abstract

Heat exchangers are frequently used in aero-engines and are known to significantly affect the surrounding steady and unsteady flow. In certain applications, they may thereby also influence the aeroelastic stability of upstream or downstream components, but there is limited research on this in the public domain. This article aims to demonstrate the influence of heat exchangers on unsteady flows relevant to aeroelastic problems. This is achieved by developing heat exchanger modeling capability for an in-house finite volume aeroelasticity solver, for which heat exchanger is represented as a porous medium, as this is the established approach in existing aerodynamic studies using commercial computational fluid dynamics (CFD) software. The governing equations for a Darcy–Forchheimer porous media model suitable for unsteady and compressible flows are presented, which are derived by the application of volume-averaging theory to the Navier–Stokes equations. The implementation of this model within the time integration method used for the solver is then described and verified by comparison of results for steady flows against an established commercial CFD solver, where close agreement between both in-house and commercial solvers has been observed. Lastly, a preliminary demonstration of the capability to model unsteady heat exchanger flows is presented by application to an aeroacoustic problem, where the interaction of the pressure waves and the heat exchanger is investigated.