Pressure field calculation in flow simulation by discrete vortex method

Abstract

In numerical simulations of fluid flow by discrete-vortexmethods, the natural processes of vorticity creation at solid boundaries and vorticity evolution in the flow domain are directly modelled. The governing equations are formulated in terms of vorticity, with the pressure terms eliminated. The calculations then yield directly the evolution of the vorticity field. From the vorticity field, streamlines and pressure fields are readily obtainable. The derivation of the pressure field involvese valuation of the time-rate of change of the velocity potential resulting from variation with time of the surface-vorticity on solid boundaries. The velocity potential, and hence the pressure,can formally have physically-inadmissible multiple values.Numerical procedures for the derivation of the pressure field from the vorticity field are detailed, which prevent the occurrence of multiple values or discontinuities in the calculated pressure.