Effect of Reynolds number and boundary layer thickness on the performance of V-cone flowmeter using CFD

The effect of Reynolds number and boundary layer thickness on the performance of V-cone flowmeter has been evaluated using computational fluid dynamics (CFD). The shear stress transport k-omega (SST k-omega) turbulence model has been adopted for closure. The performance of two V-cone flowmeters with different beta ratios (beta) viz., 0.6 and 0.7 for a fixed vertex angle (phi) of 60 degrees has been analysed as a function of Reynolds number (Re). The results show that the coefficient of discharge (C-d) increases with Reynolds number in the laminar and transition flow regimes whereas it is nearly constant in turbulent flow regime. From the results, it can be concluded that C-d is independent of Re for values equal to 4000 and beyond. Further, it is also seen that the performance of the V-cone flowmeter is not affected by the upstream boundary layer thickness if the velocity profiles having different boundary layer thickness are extracted from an axial distance of 10D and more are fed at 5D upstream of the meter. However, the meter is sensitive to the extracted velocity profile from an axial distance of 5D and uniform velocity profile being fed at 5D upstream. The value of C-d may be sensitive as a result of the pressure variation due to the obstruction.