CALCULATION OF 3-DIMENSIONAL TRANSONIC-FLOWS IN TURBOMACHINERY WITH GENERALIZED VON-MISES COORDINATE SYSTEM

An efficient numerical method for calculating the three-dimensional tr ansonic flow in turbomachinery is proposed. Instead of the Euler equat ion, streamsurface-governing equations are deduced in the generalized von Mises coordinate system to reflect the flow feature in turbomachin ery. Its main advantage is that it is easier to specify more reasonabl e initial values, i.e.:initial streamsurface position, thus accelerati ng the convergence rate of the iteration process. Moreover, to use the generalized von Mises coordinates makes the present method capable of incorporating;the calculation of the flow field, design and modificat ion of the blade contour into a unified algorithm. A rotated finite di fference scheme for the streamsurface-governing equations is construct ed, and a new measure is presented to deal with the double-value probl em of the velocity and density caused by the application of the stream functions as coordinates in the transonic flow. Three test cases were considered with the present approach to demonstrate the solution meth od for 3-D inviscid flow analysis. Numerical results confirm that the present method has rapid convergence and high accuracy.