涡街流量计涡街系数数值计算与仿真分析研究

Study on Numerical Calculation and Simulation Analysis of Vortex Street Coefficient for Vortex Flow Meter

在航天发射领域,液氧的加注系统关系到发射任务能否圆满完成,所以对于液氧流速的测量至关重要。而涡街流量计由于其性能稳定、宽量程等优点常作为液氧流速的测量仪器。经过试验仿真发现涡街流量计在低流速和高流速下涡街系数呈现出不同的特性,导致涡街流量计在低流速下其精度较低。为探究涡街流量计在低流速和高流速下其涡街系数的变化特性,对入口速度为1.0~10.5 m/s流速的涡街流场进行仿真试验,得到涡街频率和入口速度的关系图,并通过拟合曲线得到涡街频率和涡街系数的拟合曲线,最后利用得到的涡街系数曲线与平均系数进行流速的计算发现,通过曲线拟合后得到的流体流速更为精确。

In the field of space launch,the filling system of liquid oxygen relates to whether launch mission is successful or not,so the measurement of flow velocity for liquid oxygen is crucial.The vortex flow meter is often used as its measuring instrument due to its advantages such as stable performances and wide ranges.It is found that the vortex street coefficients of vortex flow meter show different characteristics at low and high flow velocities through experimental simulation so that the precision of vortex flow meter is poor at low flow velocities.In order to explore the change characteristics of vortex street coefficient for vortex flow meter at low and high flow velocities,the simulation experiment of vortex street flow field with flow velocity of 1.0~10.5 m/s at inlet is carried out as well as the relational graph of vortex street frequency and inlet velocity is obtained.Moreover,the fitting curve of vortex street frequency and vortex street coefficient is obtained through fitting curve.Finally,it is found that the fluid flow velocity obtained by curve fitting is more accurate through calculating flow velocity with the obtained vortex street coefficient curve and average coefficient.