Numerical investigation of axial seal flow in turbine cavity

Hot gas ingestion and seal flow in axial seal configuration was investigated numerically. The results show that the unmatched mesh strategy on sealing surface affects the numerical transfer because of bigger gradient of parameters which lead to higher sealing effectiveness. The steady simulation underestimates the circumference pressure unevenness downstream the vane and ignores the interaction of stator and rotor; as a result the sealing effectiveness is much bigger than unsteady simulation. The unsteady results agree with the experimental date very well. Three vortexes appear in the cavity meridian plane, and guide the flow near static disc to rotor disc for supplement the flow required by disc entrainment. Rotating hot gas ingestion and egress structures appear in seal clearance, and the ingestion flow has bigger tangential velocity. The seal clearance vortexes in seal clearance have positive effects on sealing efficiency. The transient radial velocity is 3 times bigger than time-averaged value on sealing surface. The hot gas ingestion is affected by the circumferential distribution of static pressure downstream of vane and rotor rotation.