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

This study reveals the governing mechanism of mass flow distribution within a multi-inlet, multi-outlet corotating disc cavity, providing critical insights for designing advanced gas turbine secondary air systems. An experimentally verified numerical investigation is conducted across a range of rotational Reynolds numbers Reϕ=5×106 ~ 2×107 and axial Reynolds numbers Rez=2×105 ~ 5×105, corresponding to Rossby numbers Ro from 0.01 to 0.10. Results highlight that Ro governs the internal flow and outlet mass flow distribution through two distinct regimes. In the rotation-dominated regime at low Ro, the radial outlet mass flow ratio MR decreases sharply, and a stable, dual-zone vortical structure forms. As Ro increases, growing inflow inertia disrupts this structure, causing vortices to merge, which enhances swirl uniformity and slows the rate of MR decrease. This transition dictates outlet performance: the radial outlet discharge steadily improves with Ro, while the axial outlet performance increases abruptly around Ro=0.02 before saturating.