Flowfield Investigation of a Compressor Cascade at High Incidence—Part 2: Numerical Analysis
The performance prediction of axial flow compressors and turbines still relies on the stationary testing of blade cascades. Most of the blade testing studies are done for operating conditions close to the design point or in off-design areas not too far from it. However, blade performance remains unexplored at very far off-design conditions characterised by operation under extremely low mass flows and rotational speeds which imply highly negative incidence angle values. In this work the development and validation against experimental data of a CFD model for predicting the flowfield in a compressor cascade at a highly negative incidence angle is presented. The CFD model has been tested for quite a wide range of Mach numbers, and an extensive analysis of the tools provided by the CFD code has been carried out. Several turbulence models have been tested, different meshes have been compared and various boundary condition sets have been applied to the model in order to achieve results as close as possible to the experimental data. The model is validated against the experimental results and the maximum observed deviation was found to be within reasonable order of magnitude. In addition, most trends of the properties of interest have been captured sufficiently, therefore the physical phenomena can be considered quite well predicted allowing the numerical tool to be used for further studies on similar test cases.