Sound Pressure Slopes of Turbulent and Cavitating Liquids, and a Method to Predict Such Levels

Abstract

This paper presents an author-created, unique method called the ABC method to predict sound pressure of turbulent and cavitating liquids according to ISA Standard 75.17 and is measured 1 m from the outer wall of a downstream pipe, attached to the outlet of a valve [Baumann, 2023, “Method to Establish Sound and Acceleration Levels of High Pressure Reducing Valves,” ASME Open J. Eng. 2, p. 001000-1]. The purpose of this paper is to explain how such sound pressure levels are estimated. It is accomplished by adding the results of equations in sub-sectors A, B, and C, all in dBA. This gives the sound pressure of a given valve handling water and installed in a Schedule 40 steel pipe. Additional modifiers are shown to modify the ABC method results for other pipes or fluids. The method is open and entirely based on known fluid-mechanic and acoustic laws such as Newton’s and Lighthill’s. It is claimed that such methods will give prediction results superior to those expected using the current International Electrical Commission (IEC) Standard 60534-8-4 [Baumann, 1970, “On the Prediction of Aerodynamically Created Sound Pressure Levels of Control Valves,” ASME Paper WA/FE—28, Presented at the Annual ASME Winter Meeting, November]. A table is shown presenting test data which are compared to ABC method calculated values. Additional graphical information supporting such great prediction accuracy is also shown.