Frequency-selection mechanism in incompressible open-cavity flows via re- flected instability waves

F TUERKE; L PASTUR; F LUSSEYRAN; D SCIAMMARELLA; G ARTANA

Paris

Congreso; Bifurcations and Instabilities in Fluid Dynamics (BIFD); 2015

Bifurcations and Instabilities in Fluid Dynamics Association

We present an alternative perspective on nonharmonic mode coexistence, commonly found in the shearlayer spectrum of open-cavity flows. Modes obtained by a local linear stability analysis of perturbations toa two-dimensional, incompressible, and inviscid sheared flow over a cavity of finite length and depth wereconditioned by a so-called coincidence condition first proposed by Kulikowskii [J. Appl. Math. Mech. 30, 180(1966)] which takes into account instability wave reflection within the cavity. The analysis yields a set of discrete,nonharmonic frequencies, which compare well with experimental results [Phys. Fluids 20, 114101 (2008); Exp.Fluids 50, 905 (2010)].