Numerical investigation of turbulent flow in an open rotor-stator system

The physics of fluid flow between two parallel rotating disks is the theoretical basis of the analysis and design of rotating machinery such as gas turbine. Rotor-stator system is one of the most pervasive types among rotating disk configurations. In this paper, the flow field in a rotor-stator system with its periphery totally open to atmosphere was numerically studied. The SST k-m model was employed to simulate the turbulent flow and the computational procedure was validated by comparing the computed results with experimental data in previous work. Velocity distribution in the disk cavity was obtained. Both Batchelor-type and Stewartson-type flow can be found in the cavity, and a transition zone exists for the transformation of the two flow structures. Effect on the development of flow of two governing parameters in the present configuration, the gap-ratio and the rotational Reynolds number were discussed. With the increase of the gap-ratio, the Batchelor-type region shrinks radically inward, meanwhile, the rotational Reynolds number plays a less obvious impact on the velocity profile at two radial positions we study. The present work is expected to provide profound insights for better understanding of the flow in rotating disk system.