Suppression of gas-dynamic self-oscillations in the outflow line of a gas control valve

This article is devoted to the investigation of the causes and peculiarities of high-frequency gas-dynamic self-oscillations arising in the outflow line of gas control valves. We have demonstrated that these self-oscillations result in a substantial increase in the level of dynamic loading of the control valve elements due to the occurrence of intense tonal components in the pressure fluctuation spectra in the pipeline, the vibrations of the output flange of the control valve, as well as the external noise of the whole assembly. We have provided the results of investigating the conditions for high-frequency gas-dynamic self-oscillations arising from the gas flow interaction with the control valve elements, as well as with supporting pylons of the central fairing. It is shown that an increase in the flow above a certain value of output speed (40 m/s) results in tonal components of the spectrum of pressure pulsations. We have described the measures to suppress gas-dynamic self-oscillations by means of a perforated sleeve installed in the outflow line of the control valve. Three modifications of the sleeve design have been modeled, numerical simulation of gas-dynamic processes in the control valve exhaust duct with a perforated sleeve installed has been carried out. It is shown that complete elimination of gas-dynamic self-oscillations can be made possible by installing the sleeve in the control valve exhast duct.