Influence of engine inlet and exhaust on flying wing UAV and its mechanism analysis

The inlet and exhaust can remarkably affect the pressure distribution and flow fields properties near the forebody and afterbody of the aircraft, therefore causing certain changes to the lift, drag and momentum characteristics. In order to know how inlet and exhaust affect aerodynamic characteristics of aircraft, computational fluid dynamics (CFD) numerical simulation technology was introduced to build a flying wing unmanned aerial vehicle (UAV) fairing model and an actual model, in which engine inlet and exhaust were taken into account. Boundary conditions of the actual model at the inlet and exhaust cross sections were set according to the different engine working conditions. Comparative analysis shows differences of flow fields and aerodynamic characteristics between these two models and reveals inner effect mechanism of the differences. The study on exhaust effect benefits the comprehensive aerodynamic design of aircraft/engine integrated system.