基于耦合方法的球阀偏心间隙结构数值分析

为了研究偏心间隙结构对阀门流场及管阀系统辐射声场的影响，采用流声固耦合的联合仿真方法，对含有偏心间隙结构和不含有此结构的两种流道模型展开对比分析。结果表明：两种模型的流量、阻力系数特性曲线均在球阀开启50°左右时出现转折点；偏心间隙处产生的高速射流会对阀内流场产生剧烈扰动，球阀腔体与下游管道连接处是阀内核心声源区；管阀系统的第1、第2阶模态振型为沿流道方向的振动，第3、第4阶振型为垂直于管道方向的振动；偏心半球阀的辐射噪声频谱呈宽频特性，高速射流对2 300～5 000 Hz范围内中高频段声压级幅值的提升有显著贡献；两种流道模型声压级频谱峰值点特征相似，与无偏心间隙模型的频谱规律相比，偏心间隙结构模型的频谱在相同的特征峰值点处对应更高的频率范围，且频谱响应曲线有整体右移的趋势；辐射噪声在偏心间隙结构存在的一侧具有显著的声学指向性。

Numerical Analysis of Ball Valve Eccentric Clearance Structure based on Coupling Method

In order to explore the influence of the eccentric clearance structure on flow field and radiated noise of valve,the fluid acoustic structure coupling method was adopted to carry out comparative analysis of two flow channel models with and without eccentric clearance structure.The results show that the characteristic curves of flow rate and resistance coefficient of the two flow channel models show a turning point when the ball valve opens about 50°; the high speed jet generated at the eccentric clearance will cause severe disturbance to the flow field in the valve,the connection between the ball valve cavity and the downstream pipeline is the core sound source area in the valve; the first and second order structural modal shapes of the pipe valve system are shown as vibrations along the direction of the flow channel.The third and fourth order structural modal shapes are shown as vibration perpendicular to the direction of the pipeline; the radiated noise spectrum of eccentric semi ball valve shows broadband frequency characteristics,the high speed jet has a significant contribution to the increase of the amplitude of the sound pressure level in the middle and high frequency bands in the range of 2 300 Hz to 5 000 Hz; the peak point characteristics of the sound pressure spectrum of the two channel models are very similar,compared with the frequency spectrum rule of model without eccentric clearance,the channel model with eccentric clearance structure corresponds to a higher frequency range at the same peak point of the sound pressure level characteristics,and the spectral response curve shows an overall right shift trend.Meanwhile,the radiated noise of eccentric clearance model has significant acoustic directivity on the eccentric clearance side.