The Effect of the Boundary Layer and Liquid Viscosity and Vapor on Sloshing Characteristics

Using commercial code FLUENT and the volume-of-fluid (VOF) technique adopted to track free surface, numerical investigations for the numerical models including and excluding a second set of boundary layer grid, various liquid viscosity and vapor phase are carried out in this paper. The effect of relevant parameters (boundary layer grid, viscosity and vapor) on sloshing is investigated in detail. The numerical results show that the liquid viscosity effect in boundary layer influence on sloshing pressure for established a numerical model with a second set of boundary layer grid. Energy dissipation due to viscous friction within the boundary layer leads to reduction of sloshing pressure, especially when viscosity becomes bigger, the dissipation effect is more remarkable. The results are different from Lee’s [7]. Another factor influencing the sloshing pressure is vapor phase. Compared to incompressible air, the factor leads to pressure decrease. In addition, as a result of viscous damping effect within boundary layer, the rising time of impact pressure is larger and the wave amplitude of the free surface climbing up along the tank wall is smaller in bigger liquid viscosity. The boundary layer grid also has important influence on dynamic pressure distribution along the wall. Through comparison of computational results with experimental results, we found that a numerical model with boundary layer grid can predict the sloshing pressure more accurately.