Three-Dimensional, Unsteady, Parallel Simulation of a Multi-Stage Turbine with Conjugate Heat Transfer

A computational fluid dynamics (CFD) procedure has been developed to predict the three-dimensional unsteady flow through a multi-stage axial turbine including the effects of heat transfer. This procedure simultaneously solves the unsteady Reynold's-averaged Navier-Stokes equations for the flow along with the heat conduction equation for the solid. Solution time is minimized through the use of multiple central processing units (CPUs). The blades of the multi-stage turbine move in time and the flow interacts with adjacent vane (stationary) passages through the use of a parallel, sliding-grid, inter-blade-row treatment. Described are the techniques used to solve the governing equations, the inter-blade-row treatment, and the parallelization of the overall approach. The uniqueness of this prediction method lies in the unsteady, multi-stage conjugate solution and the use of multiple combined cores. The approach is validated for the High Impact Technology Turbine designed and tested at the Air Force Research Laboratory.