L悬臂型内锥流量计可膨胀系数仿真与实验研究

Simulation and Experimental Research on the Expansibility Factor for Cone Flowmeters with L-Cantilever

为获得内锥流量计高准确度的可膨胀系数数学模型,实验样机等效直径比分别设计为0.45、0.55、0.65、0.75和0.85,利用计算流体动力学(CFD)方法对悬臂型内锥流量计进行了可膨胀系数的仿真实验,获得了可膨胀系数的CFD预测公式模型.同时,利用正压法音速喷嘴气体流量标准装置,进行了可膨胀系数的实流实验,获得了实验拟合的经验公式模型.通过对两类公式模型与实验结果的比较,得出CFD预测模型的相对误差平均值为0.77%,最大值为1.66%,均方根误差平均值为0.92%,最大值为1.97%;实验经验模型的相对误差平均值为0.25%,最大值为0.42%,均方根误差平均值为0.30%,最大值为0.51%.

In order to acquire a higher accuracy mathematical model of expansibility factor for cone flowmeters with Lcantileve,a set of test prototypes with the equivalent diameter ratios of 0.45,0.55,0.65,0.75 and 0.85 respectively were designed. Using computational fluid dynamics （CFD） method,a simulation research for the expansibility factor was carried out, resulting in a CFD predictive equation of the expansibility factor, Meanwhile,a fitting equation of the expansibility factor was obtained from the corresponding experimental research ,which was completed on the gas flow calibration device based on the critical flow sonic nozzles using the positive pressure method. Comparing the two predictive equations and the experiment results respectively,the average and the biggest values of the relative error of CFD predictive equation are 0.77% and 1.66%, respectively. As for the experiment predictive equation,0.25% and 0.42% respectively. Besides,the square averaged root error was also analyzed as following ：the average and the biggest values of CFD predictive equation are 0.92% and 1,97% respectively ;as for the experiment predictive equation ,0.30% and 0.51% respectively.