Pulsed jEt actuatoRs for SEparation control of tUrbulent flowS
This project will combine wind tunnel experiments with numerical simulations and a sensitivity analysis to improve the control authority of pulsed jet actuators (PJAs) to separated turbulent flows over a 2.5D airfoil equipped with a flap. The target of this approach is to determine the minimum net-mass-flux required by pulsed jet actuators to compensate for the momentum deficit in the boundary layer. Controlling separation contributes to a decrease in the energy demand, leading to a decrease in CO2 emissions. It also improves the manoeuvering capability, safety, and durability of the aircraft by reattaching the boundary layer and suppressing instabilities.
The present work considers the sensitivity analysis, using a hierarchy of numerical models, using Reynolds-averaged Navier-Stokes simulations and large eddy simulations for both the flow inner and outer flow. These simulations will be calibrated using wind tunnel experiments by means of a data-assimilation method. The sensitivity analysis will then allow for determining the optimal parameters of the pulsed jet actuators such as operating frequency, output velocity together with their geometry including the actuators’ outflow aspect ratio, chordwise position and inter-actuator distance in the spanwise direction. The selected technology of PJAs will be an improved design of energy efficient fluidic oscillators capable of reaching high outflow velocities with operating frequencies ranging in the natural unstable frequencies of the outer flow. Novel manufacturing techniques such as xurography will also be tested to improve the cost and fabrication time of the PJAs, as well as their integration on the wing.
Furthermore, the project will investigate the manufacturing and flow-control capabilities of dual-frequency fluidic oscillators, which may allow for further decreasing the net-mass-flux of the actuators by triggering instabilities with greater potential in altering boundary-layer separation.