超声流量计探头安装入侵长度对测量影响的估算

侵入式探头对超声流量计流场产生扰动．探头扰动造成测量误差，制约非实流标定的发展．针对探头扰动提出简化模型，根据简化模型给出探头扰动误差估算方法．与DN500和DN100两种口径的多声路超声流量计实流实验结果进行对比，估算结果与实验结果相差最大不超过0．4％．实验结果表明，随超声流量计直径减小，探头扰动造成的测量负误差迅速增大．DN100多声路超声流量计中探头扰动造成的测量误差达到-5％，且误差随雷诺数的变化率比DN500多声路超声流量计大．

Estimation on Influence of Probe Protrusion Length of Ultrasonic Flowmeter on Measurement

Probe disturbing in flow field is caused by protrusive probes of ultrasonic flowmeter. Measurement per- formance of ultrasonic flowmeter is often influenced by the probe disturbing, which restricts the development of dry calibration technique. In this paper, an estimation approach for measurement error caused by probe disturbing was proposed based on a simplified model. The effectiveness of this method is verified by experiments on DN500 and DN100 ultrasonic flowmeters respectively. It shows that the maximum estimation error is less than 0.4%. Besides, the findings of experiments indicate that measurement error caused by probe disturbing increases rapidly with the decrease of ultrasonic flowmeter diameter. -5% is achieved for DN100. Moreover, the variation of probe disturbing error with increased Reynolds number for DN100 is larger than that for DN500.