Simulation And Experimental Research On Noise Characteristics Of Noise Sources In The Water Piping System

The piping system is widely used as a transmission mass flow,momentum flow and energy flow device.It is widely used in ships,centrifugal pumps,valves and nozzles as the main noise source in the piping system,and it has great significance to noise assessment and acoustic design by accurate predicting.This paper first establishes the valve flow field numerical calculation model,the simulation of valve flow field using the CFD software,the results show that the flow field of the vortex valve is the main reason for the valve noise generated;the traditional acoustic boundary layer modeling method based on the modeling method of the acoustic boundary layer was improved by correction;valve surface fluctuating pressure calculation the extraction flow through Fourier transform will be transformed into the frequency domain acoustic simulation calculation of boundary conditions,calculate and analysis the flow noise of the valve using acoustic simulation calculation software.The flow noise of centrifugal pump is the impeller and the change of surface fluctuating pressure of a centrifugal pump volute structure caused by the surrounding fluid driven by the rotation of the impeller,so the analysis of connection mode of centrifugal pump flow simulation characteristics of the first to discuss numerical calculation of centrifugal pump rotating and stationary domain model;acoustic simulation calculation by extracting the volute of centrifugal pump the surface pressure fluctuation,using Fourier transform into the frequency domain boundary conditions of acoustic simulation,through calculation and analysis of flow noise of the volute acoustic simulation.In the simulation calculation of jet flow field and sound field,the number and quality of the grids directly affect the simulation accuracy and computational efficiency.The grid is used to select the appropriate grid.CFD software is used to calculate the nozzle flow field and extract the velocity The results show that the sound-emitting area of the water jet noise is mainly concentrated in the position of the nozzle 6-9D,and the air-Social noise is different.Through the construction of the experimental platform,the radiation noise characteristics of the noise source of the piping system in the absence of fluid motion,sound source excitation and fluid motion are analyzed and compared with the simulation calculation to verify the accuracy of the simulation calculation.