Numerical Simulation of the Shock-Tip Leakage Vortex Interaction in a HPC Front Stage

Abstract

For a single-stage transonic compressor rig at the TU Darmstadt 3D viscous simulations are compared to L2F-measurements and data from the EGV leading edge instrumentation to demonstrate the predictive capability of the Navier-Stokes code TRACE_S. In a second step the separated regions at the blade tip are investigated in detail to gain insight into the mechanisms of tip leakage vortex-shock interaction at operating points close to stall, peak efficiency and choke. At the casing the simulations reveal a region with axially reversed flow, leading to a rotationally asymmetric displacement of the outermost stream surface and a localized additional pitch-average blockage of app. 2%. Loss mechanisms and streamline patterns deduced from the simulation are also discussed. Although the flow is essentially 3D, a simple model for local blockage from tip leakage is demonstrated to significantly improve 2D-simulations on S1-surfaces.

Endwall boundary layer separation in a single-stage axial-flow low-speed compressor and a high-stagger compressor cascade

“…6. These results are similar to the findings of Adamczyk et al [23] who numerically investigated the relative flow of a high-speed fan close to stall on an axisymmetric surface of revolution between the rotor tip and the casing, see also Hoeger et al [24].…”

Effects of Low Reynolds Number on Loss Characteristics in Transonic Axial Compressor

“…However, the internal flow in a transonic compressor is more complex due to the presence of shocks. [8][9][10][11][12][13] This study investigated the effects of low Reynolds numbers on loss characteristics in a transonic compressor using numerical simulations. A comprehensive analysis of the loss mechanism was attempted by applying Denton's loss model 14) to the computational result.…”

Numerical analysis of the tip leakage flow field in a transonic axial compressor with circumferential casing treatment

“…It rolls-up into a tip leakage vortex that disturbs the main flow, especially at highly loaded operating points. Indeed, several experimental and numerical studies have shown that the tip leakage vortex interacts with the endwall boundary layer and the shock wave in the passage [1,2,3] . The abrupt change of the core vortex downstream the shock wave somewhat corresponds to a "vortex breakdown" which blocks the passage flow near the tip gap region.…”