Numerical simulation of stratified gas-liquid flow inside V-cone throttle device

Key words:  stratified gas-liquid flow  V-Cone flowmeter  trailing vortex  numerical simulation  VOF model

Abstract:

To online measure the flow rate of the stratified gas-liquid flow, the characteristics of gas-liquid stratified flow in the V-cone throttle device were numerically simulated. The effects of flow on the measurement of differential pressure were also analyzed. The formation, evolution of the vortex behind the V-cone and its influence on the flow were investigated. In combination with the gas and liquid distribution upstream and downstream of the V-cone, the effects of the gas-liquid stratified flow on the measurement of pressure difference were discussed. The results show that a large scale vortex was formed behind the V-cone. Moreover, the vortex was asymmetry in the upper and lower part of the pipe, in which the vortex length in the upper part of the pipe is bigger than that in the lower part. The end of the vortex tends to incline to the lower part of the pipe with the increase of the superficial liquid velocity. The gas and liquid distribution downstream of the V-cone demonstrates that little liquid is entrained into the vortex and no liquid appeared around the low pressure tapping, which makes a more stable differential pressure feasible and is beneficial to the measurement of the differential pressure.