The Current Gap Between Design Optimization and Experiments for Transonic Compressor Blades

The successful design of compressor blades by numerical optimization relies on accurate CFD-RANS solvers that are able to capture the general performance of a given design candidate. However, this is a difficult task to achieve in transonic flow conditions, where the flow is dominated by inherently unsteady shock effects. In order to assess the current gap between numerics and experiments, the DLR has tested the recently optimized Transonic Cascade TEAMAero at the Transonic Cascade Wind Tunnel. The tests were performed at a Mach number of 1.2 and with inflow angles between 145-147°. The results indicate satisfactory agreement across the expected working range, over which the cascade losses were consistently predicted within 3-6% error. However, some key differences are observed in the details of the wake and on the performance near the endpoints of the working range. This comparison helps validate the design process, but also informs its constraints based on the limitations of CFD-RANS solvers.