Self-sustained oscillations of a turbulent plane jet issuing into a rectangular cavity

The flow produced by a turbulent plane jet into a rectangular cavity can lead to natural self-sustained unsteadiness due to the flapping motion of the jet between the lateral walls of the cavity. This phenomenon occurs under certain geometrical conditions and in particular the nozzle exit must not be too close to a wall. If the nozzle exit is set near one of the lateral walls, the oscillations are damped and the flow reaches a steady regime. We are more specifically interested here in the oscillatory regimes. The present work considers a slightly asymmetrical configuration of the jet exit location inside the cavity. The study combines experimental and numerical modelling approaches. The numerical predictions for both single-scale and multiple-scale models are compared with the experimental data and the results discussed, Good agreement is obtained. The structural properties of the flow and the frequency of the jet flapping in the stable-oscillation flow regime have been detailed experimentally and numerically for different values of parameters, namely the location of the jet exit inside the cavity and the Reynolds number.