Zamana Bağlı Kavite Akışı Aeroakustiğinin Büyük Girdap Simülasyonu ile Sayısal Olarak İncelenmesi

Abstract

Flow along a cavity is of special interest for researchers due to the occurrence of free shear layer flow and related high levels of sound and pressure forces. In this study, turbulent flow along an open cavity at a low inlet Mach number (Ma = 0.034) is modelled by Large Eddy Simulations (LES). The velocity profiles at various stations inside the open cavity are compared to available experimental data. It is found that LES results agree with experimental data and detects the transient pressure change in the flow field satisfactorily. Transient pressure data in the flow field is evaluated in acoustic analogy. The noise generated by the cavity is compared with the established Rossiter modes and is found to be reasonable. To create an effect on the sound pressure levels (SPL), a small obstacle with quadrilateral cross section is immersed in the shear layer at three different locations. This causes that the SPL peaks are reduced compared to the case without any obstacle. Thus, cavity-induced noise form specific frequencies are redistributed to high frequency broadband noise as a result of this passive flow control method.