This paper deals with the linear stability of a liquid film flowing down an inclined plane. The Navier-Stokes equations were reduced into four evolution equations that describe the development of the film depth, the f...This paper deals with the linear stability of a liquid film flowing down an inclined plane. The Navier-Stokes equations were reduced into four evolution equations that describe the development of the film depth, the flow rate, the free surface velocity, and the wall shear stress, using the Karman-Polhausen boundary layer integral method. Thus, we were able to determine the stability threshold and approach well the critical wave number for long waves. The obtained results were found to be in good agreement with the experiments of Liu et al.展开更多
Velocity field of evaporating liquid film in a wiped molecular distillator was simulated with a computational fluid dynamics (CFD) software, and two turbulent models treating near-wall flow were compared. Differences ...Velocity field of evaporating liquid film in a wiped molecular distillator was simulated with a computational fluid dynamics (CFD) software, and two turbulent models treating near-wall flow were compared. Differences between wiped and other molecular distillations were intro-duced to explain why turbulent model should be used in this simulation. Three assumptions were made in order to simplify simulating processes. In rotating coordinate system, fixed other settings, the above two turbulent models were used, and the volume of fluid (VOF) multiphase model was also applied to tracking the liquid-gas surface. Both of the simulating results are basically iden-tical with real situation and were compared in several aspects. It was concluded that both of the turbulent models are suitable in this simulation.展开更多
The condensation heat transfer and pressure drop investigation of kerosene-air mixture gas (the range of noncondensable gas mass quantity is 5%-52%) in horizontal tube was carried out.According to the liquid film turb...The condensation heat transfer and pressure drop investigation of kerosene-air mixture gas (the range of noncondensable gas mass quantity is 5%-52%) in horizontal tube was carried out.According to the liquid film turbulent model,both heat conduction and turbulent heat transfer of liquid film at high speed of gas determine the condensation heat transfer of mixture gas.Condensation heat transfer coefficient could be predicted by Re and Co of liquid film.The correlation of condensation heat transfer coefficient was established.展开更多
文摘This paper deals with the linear stability of a liquid film flowing down an inclined plane. The Navier-Stokes equations were reduced into four evolution equations that describe the development of the film depth, the flow rate, the free surface velocity, and the wall shear stress, using the Karman-Polhausen boundary layer integral method. Thus, we were able to determine the stability threshold and approach well the critical wave number for long waves. The obtained results were found to be in good agreement with the experiments of Liu et al.
基金the National Natural Science Foundation of China(Grant No.20176037).
文摘Velocity field of evaporating liquid film in a wiped molecular distillator was simulated with a computational fluid dynamics (CFD) software, and two turbulent models treating near-wall flow were compared. Differences between wiped and other molecular distillations were intro-duced to explain why turbulent model should be used in this simulation. Three assumptions were made in order to simplify simulating processes. In rotating coordinate system, fixed other settings, the above two turbulent models were used, and the volume of fluid (VOF) multiphase model was also applied to tracking the liquid-gas surface. Both of the simulating results are basically iden-tical with real situation and were compared in several aspects. It was concluded that both of the turbulent models are suitable in this simulation.
文摘The condensation heat transfer and pressure drop investigation of kerosene-air mixture gas (the range of noncondensable gas mass quantity is 5%-52%) in horizontal tube was carried out.According to the liquid film turbulent model,both heat conduction and turbulent heat transfer of liquid film at high speed of gas determine the condensation heat transfer of mixture gas.Condensation heat transfer coefficient could be predicted by Re and Co of liquid film.The correlation of condensation heat transfer coefficient was established.
