A Robust Design Optimization of a Mixed-Flow Compressor Impeller

This paper presents the results of a design and optimization study for the impeller of a small mixed-flow compressor. The objective of the optimization is to obtain an impeller geometry that could minimize a cost function based on the specific thrust and the thrust specific fuel consumption (TSFC) of a small jet engine. The design methodology is based on generating a configurational database for various compressor geometries using ID design codes and a commercial turbomachinery design/analysis software, application of Design of Experiments to properly sample the design space, representing the cost function variations within the design space through a neural-network and then finding the optimum configuration that minimizes the cost function. A sample design optimization study showed that the designed compressor as well as the engine that it’s designed for have improved performance characteristics when compared to a typical small turbojet engine and its small radial compressor.