This paper describes a Biot-Savart discrete vortex model for simulating the flow patterns which occur when a single high-velocity inflow jet is used to stir the fluid within a circular container. The analysis is of interest in that it is representative of conditions frequently encountered in water supply service reservoirs where the mixing processes are driven by momentum from the inflow jets. The Navier-Stokes equations are solved using a Lagrangian vortex tracking procedure which is perfectly conservative and theoretically free from numerical diffusion in the classical sense. In addition, the computations are self-adaptive since the vortex elements congregate in regions of large vorticity gradient and provide high spatial resolution without an increase in computational effort. Viscous effects are incorporated into the scheme through the use of a random walk procedure whilst bed friction is simulated using a stochastic vortex decay process. The mathematical formulation has been verified by comparing predictions with observed flow data from a small-scale laboratory model. The results indicate that the discrete vortex approach has considerable promise for simulating the hydrodynamics of jet-forced recirculating flows.
展开▼
