超声流量计探头扰流影响的流声耦合研究

摘要

The disturbance flow caused by transducers is an important source of systematic deviation of ultrasonic flowmeters.In order to explore mechanism of the size and configuration of the transducer disturbing effect and calculate laboratory flow calibration factor,the flow-acoustic coupling simulation of a small-diameter flowmeter is introduced.The systematic deviation was obtained by quantitative analysis of velocity distribution along acoustic path,acoustic pressure signal on transducer surface,and the velocity measured by flowmeter.In addition,the systematic deviation under longer acoustic path length was further deduced using a piecewise weighted average method.%超声流量计测量过程中探头对流场的干扰是流量计系统偏差的重要组成部分,为探究超声流量计探头大小和结构设计所引起的扰流效应,计算实验室实流校准的修正系数,对超声探头扰流影响进行了流声耦合仿真,定量分析了声道速度分布、探头声压信号及其与实测速度之间的关系,得到了小口径流量计探头扰流的系统偏差;并利用分段加权平均的方式,进一步推导了更长声道长度情况下的探头扰流系统偏差.