Fan Optimization Under Distorted Boundary Layer Ingesting Flow

Abstract Aviation sustainability is a significant consideration in the designs of future generation aircraft. One way to achieve aviation sustainability is by reducing the overall drag acting on the aircraft. One approach being researched to achieve this goal is the implementation of boundary layer ingesting (BLI) technique. BLI technique has been shown by many researchers around the globe to be able to significantly improve the overall aircraft performance by reducing the drag and noise generated by the aircraft. However, inlets designed to ingest boundary layers tend to develop a large region of low-pressure flow which can drastically harm the overall performance of an engine placed behind the distorted flow. The success of BLI techniques heavily depends on the design of an engine fan that can deliver high aerodynamic performance even under the influence of the distorted inlet flow. The study of this paper outlines a procedure to achieve this goal by utilizing CFD-based design optimization methods. The study was broken up into three primary phases which iterated the design of an initial baseline geometry with the primary objective function being the adiabatic efficiency of the fan. The results of this study show that the optimized fans can improve the adiabatic efficiency by around 4–5% when compared to the baseline design.