超声波燃气表内部结构设计的气体流动仿真研究

Simulation Study of Gas Flowing of Internal Structure of Ultrasonic Gas Meter

摘要: 利用流体动力学仿真软件CFX对超声波燃气表腔体结构的参考设计结构(SX结构)和新设计结构(QJ结构)进行仿真研究和分析。在不同的流量点上分别仿真获得两种结构内的气体流动特性，包括两种结构的整个腔体内、腔体的XY轴向截面上及XY轴向截面中超声波测量部分的气体流速分布。对仿真结果分析显示，两种设计结构内气体流动性能非常近似。进一步分析发现，由于受到实际产品需求的影响，新改进的QJ结构比SX结构气体流速分布性能略差一些。另外，研究结果还显示与整个腔体气体流动或整个XY轴向截面上气体流动相比，超声波测量部分截面内气体流动虽然更快，但相对更均匀和稳定，有利于超声波气体流速的准确测量。

Abstract: Gas fluid dynamics of both an originally internal structure (SX structure) and a new design (QJ structure) of ultrasonic gas meter are simulated by CFX of ANSYS. Results of gas flowing velocity at typical flow points are calculated and analyzed. Gas velocity of the whole inside, the XY axis cross plane and the center part of XY axis cross plane where ultrasonic wave passes through of both the two structures is obtained. The simulation results reveal almost the same performance of gas flowing in both the SX structure and the QJ structure. Further analysis shows that comparably worse flowing performance is obtained by the QJ structure than that obtained by SX structure for requirements of real product design. Otherwise, gas fluid of the key part where ultrasonic wave passes through is in high speed; however it is more uniform and more stable than that of the whole inside or that of the XY axis cross plane, which is advantageous to accurate measurement of gas flowing velocity.