Flow Characteristics and Mass Flow Distribution Mechanism within Single-Inlet and Multi-Outlet Corotating-Disc Cavities

In the pursuit for more efficient utilization of cooling flowrate within turbine internal cavities, the present study investigates the flow characteristics of corotating-disc cavity that features single-inlet and multi-outlet configurations, and its influence on the outlet mass flow distributions. An experimentally-verified numerical investigation is conducted across a range of rotational Reynolds number Re_ϕ=5×10⁶–2×10⁷ and axial Reynolds numbers Re_z=2×10⁵–5×10⁵, corresponding to Rossby number range of Ro=0.01–0.1. A critical Rossby number of Ro=0.02 is identified, delineating between rotationally-dominated and transitional flow regime where inertial effects become increasingly influential. A novel, asymmetrical dual-toroidal vortex structure is found to govern the cavity flow, which dictates the outlet mass flow and cavity swirl distributions. The resulting cavity pressure field from the flow structure leads to opposing performance trends for the outlets, while the axial outlet’s efficiency increases with Ro, and the radial outlet’s performance is non-monotonic.