3D Mean-Stream-Line Method: A New Engineering Approach to the Inverse Problem of 3D Cascade

Abstract

The Mean-Stream-Line Method proposed by Wu and Brown (1952) for 2D cascade is developed and extended to solve the 3D inverse problem of turbomachine flow. The equations suitable to the 3D case are derived and the well-posed design conditions are discussed within the scope of the annular wall constraint of turbomachines mentioned by Cai (1983). A computer code has been programmed for this method and computation results compare well with 3D incompressible potential analytical solutions. These solutions, discovered by Cai et al. (1984), are similar to turbomachine flow. A comparison of computation results between this method and the conventional 3D potential function method is also presented. However, in solving the inverse problem, the 3D Mean-Stream-Line Method is much more simple and faster than all other methods already available. In addition, some ideas to solve direct and hybrid problems are also suggested.