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The noise generated by an isothermal single stream jet at Mach number Mj = 0.9 and diameter-based Reynolds number ReD = 1e6 is investigated numerically for an unforced confi guration and a forced confi guration with an active control device. This active flow forcing is performed with 12 Plasma Synthetic Jets (PSJs) located at the nozzle lip and acting on the axisymmetric mode of the shear layer of the main jet with a forcing Strouhal number StF of 0.14. Simulated flow and noise results are validated with comparisons to available experiments performed for identical jet conditions. The noise radiation of the reference, unforced jet is globally well recovered numerically with a limited overestimation of the experimental pressure levels, below 3 dB for most of the observations angles. In the presence of the control, the simulated interaction between the fluid injected by the PSJs and the main flow reproduces very well the development of a large coherent vortex observed experimentally in the jet shear layer. The control is also found to favour the generation of turbulence. It translates for the acoustics to an increase of the broadband noise and of the integrated pressure levels of 1.5 dB in both experiments and simulations.

On the use of Plasma Synthetic Jets for the control of jet flow and noise