Investigation of high-speed bypass effect on the performance of the surface air-oil heat exchanger for an aero engine

In the present study, the influence of an air-oil heat exchanger (SAOHE) location and orientation on engine performance is investigated using numerical predictions with a range of geometry options that match experimental data. The airflow in the unit-fin domain of a SAOHE was modeled with rotational periodic boundary conditions. Using the standard k-ɛ turbulence model, the compressible Reynolds-averaged Navier-Stokes (RANS) equations and energy equation were solved numerically. In order to validate the numerical method, experimental measurements of the velocity profile and the distribution of the pressure and heat transfer coefficient were compared to numerical results. The pressure drop, overall heat transfer coefficient, and velocity profile downstream of the heat exchanger were taken into consideration as performance metrics. An efficient numerical procedure for the installation study of a cooler having a bypass duct was conducted, and important design variables for SAOHE were clearly identified.