Abstract
Abstract
In modern under-wing-mounted high-bypass engines, the exhausted jet from the engine will interact strongly with the wing and high-lift devices. In this paper, simulations of an isothermal jet flow at Mach number Ma = 0.5 and close to a flat plate are carried out using large-eddy simulation. Far-field acoustic results are obtained via the surface integral method of Ffowcs Williams and Hawkings (FW-H). The studied cases include an isolated jet and other three configurations with the jet and a plate spaced at the distance H/D
j = 1.0, 1.5, and 2.0, respectively, from the jet axis. Validation against experimental data is carried out. Far-field acoustic results show that the overall noise levels are significantly increased for the installed cases, particularly for polar angles in upstream of the nozzle. The noise levels are increased more as the plate approaches the jet axis, indicating the installation effect is related to the H/D and the polar angle. The pressure fluctuations are shown to decay along the radial direction. The mean flow and power spectral density of the axial velocity show the characteristics of the jet flow is not significantly changed by the presence of the plate.