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 R e ϕ = 5 × 10 6 ~ 2 × 10 7 and axial Reynolds numbers R e z = 2 × 10 5 ~ 5 × 10 5 , corresponding to Rossby numbers R o from 0.01 to 0.10. Results highlight that R o governs the internal flow and outlet mass flow distribution through two distinct regimes. In the rotation-dominated regime at low R o , the radial outlet mass flow ratio M R decreases sharply, and a stable, dual-zone vortical structure forms. As R o increases, growing inflow inertia disrupts this structure, causing vortices to merge, which enhances swirl uniformity and slows the rate of M R decrease. This transition dictates outlet performance: the radial outlet discharge steadily improves with R o , while the axial outlet performance increases abruptly around R o = 0.02 before saturating.