Numerical simulation on horizontal tube falling film column flow with influence of gas crossflow

Gas crossflow changes the flow behavior, which leads to an influence on the system efficiency, especially in larger evaporators. A three-dimensional numerical simulation was performed to investigate the flow characteristics of horizontal tube falling film with gas crossflow using volume of fluid method. The deflection of the liquid column and film thickness distribution involving the effects of spray Reynolds number and gas velocity were analyzed. The results show the three-dimensional film thickness distribution around a horizontal tube. The deflection angle of the liquid column increases with the increasing of crossflow velocity and decreasing of spray Reynolds number. The liquid film in the windward side is thinner than that in the leeward side and the film with minimum thickness appears at φ = 75°–150° in “stable region.” Furthermore, the enhancement in spray Reynolds number obviously promotes film thickness in the leeward side, but the enhancement in crossflow velocity thins the film thickness, especially in the windward side.