Droplet spatial distribution is the basic information for the calculation of pressure drop and void fraction of gas-liquid two-phase flow. Based on a detailed analysis of the forces acting on the entrained droplets, o...Droplet spatial distribution is the basic information for the calculation of pressure drop and void fraction of gas-liquid two-phase flow. Based on a detailed analysis of the forces acting on the entrained droplets, one method taking account of the correction of droplet terminal settling velocity due to shear lift force was proposed to modify the droplet turbulent diffusion model. By such a modification the calculated errors of decay coefficient for horizontal oil/gas two-phase separated flow was reduced greatly. As a result, the lift force is one of the important factors to be considered reasonably during the study of droplet diffusion and spatial distribution for oil/gas transport.展开更多
Numerical simulations are carried out for wave action on a submerged horizontal circular cylinder by means of a viscous fluid model, and it is focused on the examination of the discrepancies between the viscous fluid ...Numerical simulations are carried out for wave action on a submerged horizontal circular cylinder by means of a viscous fluid model, and it is focused on the examination of the discrepancies between the viscous fluid results and the potential flow solutions. It is found that the lift force resulted from rotational flow on the circular cylinder is always in anti-phase with the inertia force and induces the discrepancies between the results. The influence factors on the magnitude of the lift force, especially the correlation between the stagnation-point position and the wave amplitude, and the effect of the vortex shedding are investigated by further examination on the flow fields around the cylinder. The viscous numerical calculations at different wave frequencies showed that the wave frequency has also significant influence on the wave forces. Under higher frequency and larger amplitude wave action, vortex shedding from the circular cylinder will appear and influence the wave forces on the cylinder substantially.展开更多
文摘Droplet spatial distribution is the basic information for the calculation of pressure drop and void fraction of gas-liquid two-phase flow. Based on a detailed analysis of the forces acting on the entrained droplets, one method taking account of the correction of droplet terminal settling velocity due to shear lift force was proposed to modify the droplet turbulent diffusion model. By such a modification the calculated errors of decay coefficient for horizontal oil/gas two-phase separated flow was reduced greatly. As a result, the lift force is one of the important factors to be considered reasonably during the study of droplet diffusion and spatial distribution for oil/gas transport.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51490672 and 51761135011)the financial supports by the National Natural Science Foundation of China(Grant No.51490673)the Petro China Innovation Foundation(Grant No.2016D-5007-0601)
文摘Numerical simulations are carried out for wave action on a submerged horizontal circular cylinder by means of a viscous fluid model, and it is focused on the examination of the discrepancies between the viscous fluid results and the potential flow solutions. It is found that the lift force resulted from rotational flow on the circular cylinder is always in anti-phase with the inertia force and induces the discrepancies between the results. The influence factors on the magnitude of the lift force, especially the correlation between the stagnation-point position and the wave amplitude, and the effect of the vortex shedding are investigated by further examination on the flow fields around the cylinder. The viscous numerical calculations at different wave frequencies showed that the wave frequency has also significant influence on the wave forces. Under higher frequency and larger amplitude wave action, vortex shedding from the circular cylinder will appear and influence the wave forces on the cylinder substantially.
