Linear Stability Analysis of Open Cavity Flow Using OpenFOAM®

Present paper deals with the modification of existing icoFoam solver (we name it—stabilityFoam) in OpenFOAM® (Open source Field Operation And Manipulation—C++ based toolbox) to solve linearized Navier–Stokes stability equations for a two-dimensional open cavity flow. The objective of this work is to obtain the spatio-temporal perturbation field around the base flow of an open cavity flow. In this view, we construct a new modified solver called “stabilityFoam” by altering the standard incompressible solver i.e. icoFoam and its associated libraries to obtain the disturbance fields around the base flow solution. The numerical simulation is performed for two Reynolds numbers (Re = 1400 and 1900). At Reynolds number = 1400, the computation showed wake mode instability in the cavity region, whereas, at Reynolds no = 1900, it showed shear mode instability near downstream of the flow. At larger times, both the perturbation structure resembles the eigenvalue solution.