均速管流量计流量系数数值校验方法研究

针对较大口径均速管流量计的流量系数获取、校验十分困难的问题,采用仿真和实验结合的方式对有效长度为300mm的均速管流量计的测量特性进行对比研究。利用标准k-ε双方程湍流模型,在直管段充分发展流下,计算该流量计端面是否粗糙处理情况下的输出差压及流量系数等测量特性,结果显示端面粗糙处理对流量计测量特性影响很小。采用数值仿真的方法对均速管流量计的流量系数进行了计算,并在实验室标准装置中对其特性进行实验验证。仿真和实验测得的流量计输出特性相似性较好,相对偏差可在±0.3%以内。该结果显示,对流量系数的数值仿真可为较大口径均速管流量计的校验提供新的思路和途径。

Study on calibration method of discharge coefficient about annubar flowmeter

For large diameter pipes,there are some difficulties to acquire or calibrate the discharge coefficient of annubar flowmeters.The goal of this paper is to do some preliminary numerical tests on acquiring or calibrating the discharge coefficients of these flowmeters.Simulations and experiments were carried out to obtain the measurement characterstics.Standard k-ε turbulence model was used in simulations at the situation of fully developed fluid.The discharge coefficient of the flowmeters were calculated and compared under the different front surface conditions of sensors.The results show that the impact of surface roughness is small.The discharge coefficients were achieved by simulation method and compared with those from experiments on the standard flowrate facility.The results indicate that the simulated dscharge coefficients are agreed with the experimental ones.The relative deviation of discharge coefficients can be within ±0.3%.This simulation method for discharge coefficients can provide some useful information for calibration of large diameter flowmeters.