水嘴内部的湍流数值模拟

Numerical simulation on turbulent flow inside faucet

水嘴内部流动复杂,研究内部湍流对其流动结构优化与湍流模型选择具有重要价值.文章选择k-ε模型、k-ω模型和RSM及它们的修正子模型等8种湍流模型对水嘴内流场进行数值模拟,试验所得出口流量与仿真所得出口流量对比,模拟结果与实验结果一致.对比分析所选区域的压强、湍流耗散率和进出口流量百分比,结果表明,压强会随着流道内部结构的改变而发生明显的变化,湍流耗散率在流体进入阀芯处和流体在阀芯顶部处的变化最为显著.通过对比进出口流量的百分比,在水嘴内部湍流模拟中,k-εstandard、RNG和k-ωstandard湍流模型的精度相较高,而k-ωBSL和SST湍流模型模拟的精度较低.

Due to the complexity of turbulent flow,the turbulence models at the present stage are all modified models.Therefore,different modified models are used to simulate the flow field in different situations,so the simulation accuracy is different.In this paper,we choose the k-εmodel,the k-ωmodel and the Reynolds-Stress model(including the modified sub model),altogether eight turbulence models,to simulate the flow field in the faucet.The rationality of the simulation results were proved by the experiment results.According to the simulated results,the pressure of the selected region,the dissipation rate of turbulence and the percentage of import and export flow are compared and analyzed.The results show that the pressure will change obviously with the change of the internal structure of the flow channel,and the dissipation rate of turbulence will be in greatest fluctuation when the fluid enters the spool and the fluid at the top of the spool.Through the analysis and comparison of the percentage of the inlet and outlet flow rate of the faucet,we can see that the accuracy of k-εstandard,RNG turbulence model and k-ωstandard turbulence model is higher than that of other models,while the accuracy of k-k-BSL and SST turbulence model is slightly lower,and the simulated Reynolds stress Omega turbulence model is less accurate than the other models under the faucet condition.