Final Activity Report Summary - ACTIVE CONTROL-JETS (Numerical Investigation of the Active Flow Control of Jets)
Aeronautical applications of flows over aircraft leading gear bay and jet exhaust flows were investigated by looking at modelling problems of open cavity and planar jets. Powerful computing resources were used to simulate transitional and turbulent low speed flows by Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) techniques. The development of the flow and its associated noise generation were studied. A simple and practical method of active flow control was successfully implemented for the cavity problem, showing good potential in reducing the drag and noise generation. Linear stability analysis was also applied in order to understand the physics behind the cavity self-sustained oscillations.
Moreover, LES and DNS of the isolated planar jet were performed and the obtained results were analysed to enhance the understanding of the physics underlying the development of low-speed jets and sound generation. In particular, the effect of the nozzle exit profile on the jet development and sound generation was studied.
LES of the interactions between primary planar jet and small-scaled synthetic jet were also carried out. In the simulations the real geometry of the synthetic jet was replaced by a simplified model of oscillating channel flow. This simplified model was found to be appropriate for the purposes of the current research. It was demonstrated that, as a result of interaction between primary and control jets, the primary jet was vectored towards the control jet, thus potentially increasing the manoeuvrability of the jet engine.
Moreover, LES and DNS of the isolated planar jet were performed and the obtained results were analysed to enhance the understanding of the physics underlying the development of low-speed jets and sound generation. In particular, the effect of the nozzle exit profile on the jet development and sound generation was studied.
LES of the interactions between primary planar jet and small-scaled synthetic jet were also carried out. In the simulations the real geometry of the synthetic jet was replaced by a simplified model of oscillating channel flow. This simplified model was found to be appropriate for the purposes of the current research. It was demonstrated that, as a result of interaction between primary and control jets, the primary jet was vectored towards the control jet, thus potentially increasing the manoeuvrability of the jet engine.