Fully Coupled Body Force–Engine Performance Methodology for Boundary Layer Ingestion

Abstract

Because of their potential reductions of fuel consumption, disruptive propulsion concepts such as boundary layer ingestion have lately earned the attention of the aerospace community. Because of the increased level of interactions brought by the tight airframe–propulsor integration, an accurate assessment of this benefit requires a detailed study of the engine behavior from both an aerodynamics and an overall performance standpoint. In this context, this Paper presents a fully coupled methodology that integrates a zero-dimensional thermodynamic cycle analysis of the core and a three-dimensional body force representation of the fan stage into a single numerical computation. This approach allows the efficient simulation of fan–distortion interactions and engine overall performance in terms of accuracy vs computational cost tradeoff, making it well suited for conducting full aircraft–engine computational fluid dynamics calculations. The coupling is demonstrated in the assessment of boundary layer ingestion impacts on the small DGEN380 turbofan. Results provide a quantification of such impacts on fan efficiency, engine power demand, thrust specific fuel consumption, flow distortion transfer, and fan stage aeromechanical response, for different engine net thrust settings.