Large Eddy Simulation of Hydrofoil Tip Leakage Vortex

Abstract

The axial-flow turbomachinery is important in water supply and drainage. However, there is a gap between the blade tip and the casing, which is easy to cause tip leakage vortex. Tip leakage of axial-flow turbomachinery has bad impact on the operation stability. In this case, the numerical simulation is used to study the simplified hydrofoil model with clearance. Then the change of tip leakage vortex core position and the pressure distribution are analyzed. Results show that with the fluid flows downstream, the longitudinal position of the tip leakage vortex core first drops and then rises. On different streamwise planes, the vortex core has the lowest pressure. From the downstream to the vortex generating position, the vortex core pressure decreases gradually, and the cavitation is most likely to occur at the location where the vortex occurs.