A Method to Predict Sound Levels from Flow Control Valves

초록

A constant flow-rate control valve provides effective distributions and controls of running water in a pipe system. The noise characteristics were measured to reveal the noise sources depending on pressure differences across a valve. Valve noise is mostly dominated by bubble dynamics under cavitating conditions. In this study, the sound powers from a flow control valve of a constant flow-rate are effectively normalized. Flow-excitated dynamic systems for which there is no strong coupling between the flow and the system response can be described using a linear source-filter model. On this assumption, the normalized sound powers can be decomposed of noise source function and a response function. To find noise sources, pressure spectra measured over a range of pressure differences are transformed into the product of two non-dimensional frequency functions : Spp(He,fca,x/D) = F(fca) G(He,x/D) This study characterizes spectral features associated with the noise sources in two different modes of cavitation.