Windage Rise and Flowpath Gas Ingestion in Turbine Rim Cavities

Typically cooling air must be metered into cavities bordering turbine disks to offset cavity air temperature rise due to windage generated by air drag from rotating and stationary surfaces and the ingestion of hot mainstream gas. Being able to estimate the minimum amount of cooling air required to purge turbine rim cavities accurately is important toward providing optimum turbine cycle performance and hardware durability. Presented is an overview of a method used to model windage rise and ingestion on a macroscopic scale. Comparisons of model results to engine test data are included.