Generation of intense aerodynamic noise and vibration from a high pressure gas valve might be closely related to the flow patterns particular to the valve trim geometry and the flow condition. Characteristics of acoustic modes inside a model valve and of dynamic forces acting on the valve stem are investigated. Four typical patterns of the flow in the supersonic regime are observed by schlieren photography and the two extreme patterns are simulated by a numerical analysis of the FLIC method. In an intermediate range of pressure ratio and valve opening, the radiated noise and the fluctuating force are most intense, and discrete components with a frequency of more than 9 kHz are noted in the spectra. The high noise as well as the oscillation can be reduced or eliminated by using a plug contour where the expanding flow attaches to the seat over a wide range of pressure ratios.
|Number of pages||17|
|Publication status||Published - 1984 Dec 1|
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