tip leakage vortex further develops beyond the shock leading to a better prediction of velocity and pressure fluctuations. Nomenclature BP F Blade Passing Frequency of the IGV for Rotor 1 (R1) C Rotor 1 axial chord IGV Inlet Guide Vane LDA Laser-Doppler-Anemometry LE/T E Leading Edge / Trailing Edge R1 Rotor 1 T Passage time period of IGV with respect to R1 (U)RAN S (Unsteady) Reynolds-averaged Navier-Stokes U i,j U i,j Velocity gradients: i,j (∂u i ∂x j) 2 ∆x + , ∆y + , ∆z + Normalized wall cell dimensions ZDES Zonal Detached Eddy Simulation

In the present study, the influence of the inlet condition on the tip clearance flow of an axial compressor is investigated. Two different zonal detached eddy simulations (ZDES) computations are carried out and compared to Reynolds-averaged Navier–Stokes (RANS) and unsteady RANS (URANS) computations as well as to experimental data. A rotating distortion map of the flow cartography is set as inlet condition for the first ZDES computation. An azimuthally averaged inlet condition is used for the second one and uncouples the rotor tip-leakage vortex flutter phenomenon, which stems from the arrival of the inlet guide vane wake from the behavior inherent to the rotor tip-leakage vortex. In the studied configuration, the inlet guide vane tip vortex reveals to lower the effects from double leakage on the rotor. The topology of the rotor tip-leakage vortex is described, and its development is analyzed.

Corner separation is known to limit the operability of aeronautical compressors. Dedicated control devices such as guide fins are envisioned to reduce its negative effects. This paper presents a methodology based on RANS (Reynolds-Averaged Navier-Stokes) computations enabling to select guide fins efficient for that purpose. This methodology is applied to a reference case of linear compressor cascade operating at low Mach number (∼0.11). A set of 17 parameters is used to define two design spaces of interest, from which guide fins are generated. From then, an automated process generates and merges an unstructured mesh built around each guide fin with a fixed, structured mesh of reference representing a single channel of the cascade. Finally, RANS results on the resulting hybrid mesh are obtained using the Computational Fluid Dynamics solver elsA. This set up has proven successful in evaluating automatically hundreds of guide fins of various shapes. Several geometries illustrate the diversity of the design space. A selection of guide fins is then evaluated experimentally. Evolutions of the losses downstream of the cascade are compared to their respective RANS predictions, and to the reference case without guide fin. These experimental results validate the implemented methodology and show encouraging results in terms of loss redistribution brought by the control device.