Mechanism of end-wall fence in controlling secondary flow of compressor cascade

The numerical simulation has been carried out on 3D viscous flowfield in CDA (controlled diffusion airfoils) compressor cascade with and without endwall fences on different streamwise locations and different geometrical parameters. The results show that endwall fence can control secondary flow by decreasing the influx of pressure side of horse vortex into passage vortex and forming reversed fence vortex. The optimal fence is located in the foreside of the passage, about 30% pitch far away from the pressure surface, with the height of 1/3 incoming boundary layer thickness and the length of 3/4 axial chord.