Development of Numerical Methods for Turbulent Flow in Complex Rotating Systems

Doktorsavhandling, 1992

A computer code has been developed to predict three-dimensional incompressible turbulent flow in complex rotating geometries. The application in mind is turbomachinery in general. However such a code is able to treat a large number of problems in fluid mechanics. The code has evolved gradually, so numerical methods are presented for computing laminar flow, turbulent flow using the k-e model, turbulent flow using a full Reynolds stress turbulence model which includes the effect of a rotating frame of reference. Some work has been done to reduce numerical diffusion. Free-stream induced transition from laminar to turbulent flow is computed. Wall boundary layers has been treated with wall-functions as well as with a low Reynolds number version of the full Reynolds stress turbulence model where the boundary layer is resolved. The numerical formulation is based on control-volumes and uses structured grids in a general non-orthogonal coordinate system. Both formulations with staggered and non-staggered velocities have been used in this work. Test cases are; Rotating Couette flow, flow in a pipe with a constriction, Jeffery-Hamel flow, uniform flow using a cylindrical mesh, flow inside a channel with a smooth expansion, flow in a ventilated room with inclined floor, flow in a cascade, driven cavity flow, flow over a rotating/non-rotating backward facing step, flow in a rotating/non-rotating channel, flow over a plate where transition occurs.