Three-Dimensional Analysis of Incompressible Flow Over an Open Cavity Using Direct Numerical Simulation: From Linear to Saturated Regime

Abstract

The features of the incompressible flow over a rectangular open cavity are studied both numerically, using linear stability analysis, and experimentally in previous works by the authors [5, 7]. Those approaches refer to different states of the flow. The numerical analysis refers to a linear small perturbation superimposed over a two dimensional steady state, while the experimental work studies the complete saturated flow regime, with spanwise walls. Even with such different conditions, both approaches have revealed common features, with the main structures of the experimental flow being recognizable from the corresponding modes of the linear analysis, albeit with certain differences, mainly in the oscillating frequencies [7]. The aim of this work is to fill the breach that separates those two states studying the saturation of the flow using a three dimensional non-steady Direct Numerical Simulation (DNS). In this first stage periodic boundary conditions in the spanwise direction will be considered.