The Vortex&Wave Tracker software is utilized to perform joint computations on the impeller of a turbojet engine fan, incorporating several variations of input devices. These computations employ various turbulence description approaches, ranging from RANS to zonal IDDES. To identify the features of the generation and transformation of acoustic disturbances, a comparison of the computation results with a cylindrical channel and model input disturbances in the URANS and LES representations is used. This comparison confirms a qualitative change in the transformation of acoustic disturbances when adopting a vortex-resolving approach to describe the turbulence. Vortex-resolving calculations of the supersonic air intake system with a make-up window during takeoff and the fan impeller show that, in all the variants considered, the flow inhomogeneity in front of the impeller is unacceptably high. The noise of the system differs from the noise of the impeller in a short nacelle in its structure, pattern, and level. It is a combination of the noise of the fan, which has lost its tonal structure when interacting with turbulence in the channel, and the noise from poorly streamlined air intake walls. The calculation shows that, when a grid is added to the window, it becomes a source of its own tonal noise, capable of increasing the total level in the far field to 5dB.
V. A. Shorstov (Sun,) studied this question.