Dr. Jeff Defoe (University of Windsor) will visit the faculty of Aerospace Engineering of TU Delft on 3 May 2017. He will hold a talk in lecture room A starting at 11 a.m., on: "Fan and Compressor Performance Scaling with Inlet Distortions". The seminar is open to the public.
Applications such as boundary-layer-ingesting fans, and compressors in turboprop engines require continuous operation with distorted inflow. In this presentation, machines representative of these two applications are studied. The objective is to determine how fan and compressor performance scales as the type and severity of inlet distortion varies at the design flow coefficient and corrected rotor speed.
A distributed source term approach to modeling the rotor and stator blade rows is used in numerical simulations. Different approaches are used for the low-speed fan and transonic compressor, but both have been shown to capture overall stage performance and flow field behavior with distortions having length scales much longer than the blade pitch. For the low-speed fan, viscous losses are not included so efficiency is not assessed but instead changes in diffusion factor are examined as a proxy for efficiency changes. For the transonic compressor, efficiency changes are directly assessed in addition to diffusion factor changes, allowing the two metrics to be related.
Distortions in stagnation pressure and stagnation temperature are considered. It is found that the diffusion factor/efficiency changes scale approximately linearly with the intensity of the distortions (i.e. the ratio of minimum to maximum values) but that changes in distortion location relative to the fan/compressor axis produce nonlinear changes in these metrics. Combinations of distortions are also studied and it is found that the metric changes associated with the combined distortion can be predicted by summing the metric changes associated with the individual constituent distortions.