Numerical study of windage mitigation in a radial inflow co-rotating cavity with the vortex reducer

Abstract

This work numerically investigates the effects of the vortex reducer tube length and the drum hole geometry on the pressure loss, windage torque, and flow structure in a compressor disk cavity, with the aim of enhancing the secondary air system efficiency. The computational results reveal that, at a given flow coefficient, increasing the rotational Reynolds number (Reθ = ρωR2/μ) reduces both the static pressure loss coefficient (Cp = ΔP/0.5 ρω2R2) and the torque coefficient (Cm = M/0.5ρω2R5). At high rotational speeds, the growth rate of the pressure drop ΔP with rotational speed is large, while that of the torque M is small. At low rotational speeds, the growth rate of ΔP becomes smaller, whereas that of M becomes larger. The size of the obround drum holes significantly affects the pressure and windage losses, while the influence of the vortex reducer tube length is relatively weak. Enlarging the drum hole size can effectively reduce Cp and Cm. Furthermore, distinct optimal tube lengths are identified for minimizing Cp and Cm respectively, providing design guidelines for lightweight, high-performance rotating structures.