WATER SURFACE OSCILLATION ANALYSIS OF SIDE CAVITY FLOW USING SHALLOW-WATER MODEL WITH UNSTRUCTURED GRID

Abstract

Numerical simulation and experimental measurement are used to investigate the resonant instabilities in flow past a side cavity. The shallow water flow equations are solved by using the finite volume method with an unstructured grid system. The flow characteristics of numerical and experimental results are compared and found to be in favorable agreement qualitatively between the results, especially behavior of a long term and large scale oscillation mechanism. The frequencies of oscillation mode analyzed by POD (Proper Orthogonal Decomposition) are compared to theoretical and semi-empirical formulae, from which the feature of the short term oscillation and the long term one are distinguished. The condition which provides an intense long term oscillation are discussed by using experimental and numerical results.