Study On Simulation And Experiment Of Installation Requirement For V-Cone Flowmeter

Difference pressure flowmeter is one of the most widely flowmeter. V-cone flowmeter, which appears recently, has the advantages of low permanent pressure loss, less straight pipe require of upstream and downstream, smudge resistance ability and so on. Therefore it has become an interest-raising research topic in the recent years. Owing to late appearance of the V-cone flowmeter, there is not uniform national standard yet. It has no correlative report about the influence of installation requirement on the performance of the V-cone flowmeter at home and aboard. The study on the influence of installation requirement on the performance of the V-cone flowmeter is developed in this paper.This subject is started with the influence of installation requirement on the discharge coefficient of the V-cone flowmeter. The influence of the upstream elbow and the incremental condition on the performance of the V-cone flowmeter is studied by numerical simulation study with 100mm caliber and three equivalent diameter ratioβ= 0.45,0.65,0.85. And the influence of the half-moon orifice on the performance of the V-cone flowmeter is studied by numerical simulation study with 800mm caliber. We also study the influence of the upstream elbow on the performance of the V- cone flowmeter by experiment. The CFD simulation forecast is presented and compared with the results of experiment.The flow field of the V-cone flowmeter with 800mm caliber in the requirement of interference flow with the half-moon orifice is simulated by the calculating fluid dynamics simulation software Fluent. The simulation mainly includes the foundation of Gambit geometry model, comparison and choice of standard k-εon flow model, and calculation of flow filed. The comparison of simulation data and baseline experiment data shows that the existence of the interference flow with the half-moon orifice destroys the symmetry of the velocity filed of the V-cone flowmeter badly. It is also shown that the error△C% between discharge coefficient at upstream 5D interference flow and baseline is -1.3%, and that error at upstream 3D is 7.9%. Therefore it can be forecasted that there is almost no influence on the performance of the V-cone flowmeter by adding the interference flow with the half-moon orifice at forward 5D or even farther.Using the Fluent simulation software, the flow filed of the V-cone flowmeter with 100mm caliber at upstream 0D,1D and 2D incremental installation requirement is simulated by the RNG k-εonflow model. The simulation data and flow filed analysis shows that the discharge coefficient error△C% relative to the baseline in the forward incremental installation requirement is 0.6% ~±0.9% (<±1%) .Using the Fluent simulation software, the flow filed of the V-cone flowmeter with 100mm caliber of upstream elbow installation requirement is simulated by the RNG k-εonflow model. The infection rule of single elbow, double elbow in same plane, and double elbow out of plane at cone forward 0D,1D,2D on the discharge coefficient of the V-cone flowmeter with three values ofβ. The comparison to the results of experiment in the same installation condition shows that the change rule of the discharge coefficient of the V-cone flowmeter in upstream elbow installation condition is consistent with that of baseline. The bigger value ofβis, the greater influence of upsteam elbow on the discharge coefficient. The influence of double elbow on the performance of the V-cone flowmeter is smaller than that of single elbow with the same length of the forward straight pipe.