关键词: V形内锥, 等效直径比, 计算流体动力学, 雷诺数, 流出系数, 流量计, 前后锥角

Abstract: By combining the computational fluid dynamics (CFD) simulation experiment with the real physical calibration experiment, this study is to discover the characteristics of the discharge coefficient of V-cone flowmeter. Here, the turbulence model is RNG k-ε. The key factors include different values of equivalent diameter ratio β, fore-and-aft V-cone angle and the Reynolds number. The pipe diameter of all the prototypes is 100 mm with the β, 0.50, 0.65, 0.85, respectively, the fore V-cone angle, 40º, 45º, 50º, respectively, the aft V-cone angle, 120º, 130º, 140º, respectively. Therefore, there are 27 tested models in all. The medium for simulation is water of 293 K. The 27 characteristic curves are obtained from the numerical simulation. In order to further verify the computational results, a new automated special device for calibration is set up, which depends on an established water calibration and test device. From the both test data, we discover that the discharge coefficient of V-cone flowmeter relates not only to the Reynolds number, but also to the values of equivalent diameter ratio β, fore-and-aft angles of V-cone. Firstly, the discharge coefficient increases while the β is decreased, and it is influenced more easily by Reynolds number while the β is increased. Secondly, if the β keeps the same value, the fore V-cone angle is crucial, and the aft can influence the linearity to a certain extent. Thirdly, larger fore V-cone angle will weaken the influence of the Reynolds number. The average error of simulations is approximately 5%, the maximum, less than 10%.

Key words: Computational fluid dynamics, Discharge coefficient, Equivalent diameter ratio, Flowmeter, Fore-and-aft V-cone angle, Reynolds number, V-cone