Numerical Simulation Based Study Of Cage Valve Flow Noise Characteristics

The control valve is widely used in modern automation and industrial field,so the study about the flow noise characteristic of control valve is very meaningful.It is very difficult to measure noise of control valve because of its complex flow field.Previous studies generally use experimental method,and then get some parameters of valve.This study attempts to apply the method of numerical simulation to analyze the flow noise characteristics of the valve.According to the basic theory of CFD and CAA,the flow field model and sound field model will be established.Four opening degrees of valve,which contains opening degrees of 100%,70%,40% and 10%,are chosen to do numerical simulation by using Fluent and Actran.Some important parameters of flow and sound field can be gotten by numerical simulation,such as pressure,velocity,turbulence intensity,sound directivity characteristics and sound pressure.According to the results of flow field,it can be obtained the relationship between different opening degree and flow coefficient.The results also show that the main change area of pressure and velocity occurs in the window of valve sleeve,where can be the predicted place of noise source.This research also analyzes the reasons for the different changes of different opening degree of valve.Two groups of monitoring points are used to analyze the noise characteristics,which is located on internal and external of valve.The results show that the spectral distribution of noise inside of valve is different between low frequency and high frequency.The sound pressure,which is located at the middle of valve,is higher than the region of downstream and upstream.The distribution of sound directivity characteristics shows that regulation and symmetry of graph in low frequency is better than high frequency.Finally,the main reason for the noise generated inside the valve can be gotten by the analysis of flow field and sound field.The results of noise characteristics for research of control valve have some reference value.