Investigation of Impact of Jets with Zero-Net-Mass Flux on Flow in Curvilinear Diffusers

The impact of the blowing of jets with a zero-net-mass-flux (JZNMF) from the wall of a plane diffuser with expansion $1.8$ on a turbulent separation flow is studied using a hybrid method for solving the veraged Navier–Stokes equations and the implicit method for large-sized eddy simulation (RANS/ILES method). The total pressure losses are shown to decrease by two times with the corresponding selection of the JZNMF frequency and amplitude. In this case, the level of the total pressure fluctuations at the diffuser outlet decreases by two to three times and the level of fluctuations of the longitudinal velocity components decreases by $1.2$$–$$1.5$ times. The impact of the velocity at the diffuser inlet on the JZNMF efficiency is studied. The dependences of the impact of the JZNMF frequency and amplitude on the total pressure losses and the distribution of the averaged parameters of the flow and turbulence in the outlet cross section of the diffusion are obtained.