APPLICATION OF INVARIANCF ANALYSIS OF VELOCTTY-GRADIENT TENSOR TO EVALUATION OF LOCAL PROPERTIES OF THREE-DIMENSIONAL VORTEX STRUCTURE OF WATER INTAKE FLOW

Abstract

In order to examine local properties of three-dimensional complex flows around a water intake with locally varying strengths of shear and vorticity with isolated vortices, a new method of flow diagnostics based on the invariants of the velocity-gradient tensor has been proposed and applied to the analysis of the laminar flows in intake bay. The results indicate that the flow topology can be effectively found by the phase plot of the second and third invariants of the pressure-gradient tensor, while vortex structure can be better identified by the three-dimensional plots of the second invariant of the rotation tensor and the vorticity number.