On the Development of Viscous Solvers for Computation of Transient Flows in Turbomachines

This paper focuses on development and validation of a viscous solver for the computation of unsteady flows in turbomachinery blade rows and stages consisting of rotors and stators. The code has been evolved from steady-state single flow solvers developed by Wiedermann based on time-marching finite difference schemes. A two-equation eddy viscosity model is applied, and the wall boundary conditions are determined by the y^+ -distance of the first grid line away from the wall. For the solution of transient flow fields the original time-stepping algorithm is replaced by a time-accurate scheme. The emphasis of the code validation will be on blade-row interaction in a complete turbomachinery stage. A 3-D example will be discussed and those parameters evaluated which are important for actual blading design.