Numerical Investigation of Gas ingestion into the Upstream Cavity with High-positioned Cooling Air Inflow

摘要

The fluid flow in the area of gas turbine rim seals, effectiveness are influenced by the interaction of the rotor and the stator disk and by the external flow in the hot gas annulus. The resulting flow structure is all 3-dimensional and time-dependant. The requirements to a sufficiently accurate numerical prediction for the cavity flows are discussed in this paper. The results of different numerical approaches are presented for an axial sealing configuration based on the experimental facility in the Key National Laboratory in Beijing University of Aeronautics and Astronautics. This covers a full simulation of the time-dependant flow field in a stage experimental turbine including the main annulus and the rim cavity. This configuration is simplified in order to identify a method providing the best compromise between a sufficient level of accuracy and the least computational effort. Through the numerical simulation, it presented the flow patterns and the characteristic of the gas ingestion based on the real experimental facility with high-positioned cooling air inflow, and drew an understanding of the influence the vane trailing edge vortex, the interaction between vane wakes and blade boundary layer on the gas ingestion.