Performance of Cascade of Blades in Two Phase Flow (Modeling and Numerical Calculation)

抄録

A cascade flow, which is the most fundamental phenomenon in turbo-machinery, is calculated numerically under bubbly two-phase flow conditions. The governing equations for two-phase flow are formulated with emphasis on local density distribution and sound velocity distribution caused by slippage between the bubbles and the surrounding liquid. The numerical results reveal some characteristics of the bubbly blade to blade flow. The flow has the characteristics of a compressible flow ; it is compressible flow, of which pressure and Mach number are widely distributed. The void fraction around the stagnation point of the blade decreases due to the slippage driven by the pressure gradient, and the flow around the stagnation point becomes similar to an incompressible flow. The pressure recovery on the blade surface decreases due to accumulated voids in the low pressure part on the blade. The relaxation zone of the shock wave becomes thicker due to the slippage.