평면 충돌제트의 불안정특성(2) -원통음-

Abstract

The objective of this study is to obtain the instability characteristics of the plane jet impinging on a circular cylinder associated with the cylinder-tone. It is found that the characteristics depends upon the ratio of the cylinder diameter to the nozzle width, , and the jet velocity. When the ratio is moderate the cylinder-tone is similar to the edge-tone. With increase of the ratio, its charateristics becomes similar to that of the plate-tone in which only the high-speed tone associated with turbulent jet is generated. When < 1, the frequency range, especially the lower limit of frequency, is significantly influenced by the cylinder diameter. At around = 1/2, while low speed tones are induced with the antisymmetric mode of instability and affected by the vortex shedding from the cylinder, high-speed tones are generated, at first, with the symmetric mode of instability, and then, with antisymmetric mode, as the jet velocity increases.