The tip and hub leakage flow of a repeated two stage compressor

End wall flow of a repeated two stage compressor at design and choke condition were studied by numerical simulation. The vortex near the hub depends on the traverse pressure gradient and sheer force induced by the hub rotation. At the design and the choke condition the hub leakage vortex is the dominant secondary flow. The position and trajectory of the tip leakage vortex at design and choke condition were also studied. At the design condition the tip leakage vortex traverse the blade channel and impinge on the middle chord of the suction surface of the adjacent blade. At the near choke condition the tip leakage vortex would go downstream along the streamwise direction. The composition of the tip vortex was also studied. It is clearly to distinguish the strong and weak part of the tip leakage vortex for design condition while at the near choke condition there is no evident weak part of the tip leakage vortex.