Zonal Detached-Eddy Simulation of tip-leakage flow sensitivity for a compressor rotor

The tip-clearance size of compressor rotors has a big effect on both performance and off-design conditions. Increasing the value tip gap can lead to reduction in efficiency surge margin about 1 %. Mechanical constraints impose minimal clearance order for operate while further would generally be beneficial aerodynamically. However, sensitivity show more complex tendencies. For example, some studies have shown non-linearity decrease with size, an optimal different from zero machines flow These conditions are not precisely understood influence structures developing region is completely resolved. Parametric RANS simulations experiments made real progress possible comprehension tip-leakage (TLF) but detailed resolution only accessible through higher numerical resolutions. In this study, around rear rotor 3-stage high-pressure axial been simulated hybrid RANS/LES approach, three sizes, at peak efficiency. Zonal detached-eddy simulation (ZDES) enables LES out boundary layers following separation points, limited number elements blade passage. present case, upstream third rotor, casing layer (modelled RANS) thick immerses gaps investigated. detachment vortex (TLV), ZDES model switches thus treating convection TLV passage LES. Generally, approach preserves farther than RANS, lower diffusion less losses. Regarding tip-gap results confirm classical tendency literature increased losses increasing gaps. intense generates larger gap. study also investigates point roll-up, trajectory distribution vorticity core its evolution along related ratio between boundary-layer integral quantities size.