Shock-vortex interaction in a transonic turbocompressor

Tip-vortices on axial compressor rotor blades develop due to the pressure difference between suction and pressure side and roll up above the suction side. On a transonic rotor blade the leading edge thickness causes a bow shock which changes over to an expansion wave on the suction side. On the pressure side the shock is being intensified and crosses the passage hitting the neighbouring blade on its suction side. The tip-vortex has to cross the passage shock. The shock-vortex interaction leads to a sudden and strong deceleration of the flow, a rapid expansion of the vortex and, as a consequence, to a strong change in the vorticity distribution of the vortex. Depending on the intensity of the shock-vortex interaction, vortex breakdown occurs and possibly causes compressor stall.