EXPERIMENTAL STUDY OF VELOCITY DISTRIBUTIONS IN THE TRANSITION REGION OF PIPES  

作　　者：LIU Yong-hui DU Guang-sheng LIU Li-ping SHAO Zhu-feng ZHAI Cheng-yuan 

机构地区：[1]School of Energy and Power Engineering,-Shandong University, Jinan 250061, China,

出　　处：《Journal of Hydrodynamics》2011年第5期643-648,共6页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10972123,10802042);the Natural Science Foundation of Shandong Province (Grant No.Y2007A04)

摘　　要：The accuracy of an ultrasonic flowmeter meaurement depends on the profile-linear average velocity. But this velocity in the transition region is not available at the present. In this article, the velocity in the transition region in pipes is studied by experimental methods. The Particle Image Velocimetry （ PIV ） is used to measure the flow field in the transition region in pipes, and the measured results from PIV are in good agreement with the Westerwell＇s experimental data. Based on the experimental data of PIV, the curves of the profile-linear average velocity in the transition region against the Reynolds number in the range from 2 000 to 20 000 are obtained, and it is shown that the coefficient k is constant when the Reynolds number is in the range of 2 000-2 400 and 6 000-20 000, and the coefficient k is increasing when the Reynolds number is in the range of 2 400-6 000. The results of this article can be used to improve the measurement accuracy of the ultrasonic flowmeters and as a theoretical basis for the research on the transition flow.The accuracy of an ultrasonic flowmeter meaurement depends on the profile-linear average velocity. But this velocity in the transition region is not available at the present. In this article, the velocity in the transition region in pipes is studied by experimental methods. The Particle Image Velocimetry （ PIV ） is used to measure the flow field in the transition region in pipes, and the measured results from PIV are in good agreement with the Westerwell＇s experimental data. Based on the experimental data of PIV, the curves of the profile-linear average velocity in the transition region against the Reynolds number in the range from 2 000 to 20 000 are obtained, and it is shown that the coefficient k is constant when the Reynolds number is in the range of 2 000-2 400 and 6 000-20 000, and the coefficient k is increasing when the Reynolds number is in the range of 2 400-6 000. The results of this article can be used to improve the measurement accuracy of the ultrasonic flowmeters and as a theoretical basis for the research on the transition flow.

关 键 词：ultrasonic flowmeter Particle Image Velocimetry （PIV） the profile-linear average velocity transition region PIPE 

分 类 号：O4-33[理学—物理] TQ021.1[化学工程]