液压集成块湍流模型修正及内流特性分析

Turbulence Model Correction and Internal Flow Characteristics Analysis of Hydraulic Manifold Blocks

基于粒子图像测速技术(PIV)建立了带有刀尖角容腔的直角转弯流道流场的数值计算模型,并进行三维流场仿真。通过将数值计算得到的典型涡系结构与实验结果进行对比,考察了工程上常用的7种湍流模型对带有刀尖角容腔直角转弯流场的预测性能。通过定义权重误差K,筛选出S-A模型作为基础湍流模型并对其进行了参数修正。结果表明,当S-A模型Cb1取值从默认值0.1355修正为0.17时,出流方向正对刀尖角容腔模型权重误差值上升25.0%,入流方向正对刀尖角容腔模型权重误差值下降34.7%,修正后的S-A湍流模型对两种直角转弯流场的综合预测精度有所提高。运用筛选修正后的S-A湍流模型分析了4种典型直角转弯流道的内流特性,结果表明圆弧过渡直角转弯流道相比于带有刀尖角容腔的转弯流道具有更小的压力损失。

A corresponding numerical calculation model was established and the three-dimensional flow field simulation was carried out based on the particle image velocimetry（PIV）measurements of the flow fields of right-angle turn channels with cavities.The predictive ability of the 7kinds of turbulence models commonly used in engineering were investigated by comparison the typical vortex structure of numerical results.By defining the weight error function K,a S-A model was selected as the basic turbulence model and were modified.The results show that when the S-A model Cb1 is modified from the default value 0.1355 to 0.17,the weight errors of the outflows facing to the right angle cavity model increase by 25.0%,and the weight errors of the inflows facing to the right angle cavity model decrease by 34.7%.In general,the predictive accuracy of modified S-A turbulence model is improved in forecasting the flow fields of two kinds right-angle turn channels with cavities.The internal flow characteristics of four typical right angle channels were analyzed by using the modified S-A turbulence model,the results show that the arc right angle flow passages have smaller pressure losses than that of the turning flow channels with cavities.