Low-capillary number or surface tension dominated flows are found in a number applications, ranging from small scale microfluidics up to larger scale analysis of microgravity sloshing. This paper evaluates the possibility of modelling of surface tension dominated multiphase flows using an Eulerian volume-of-fluid (VOF) approach with high-resolution surface capturing. With the aim of improved st...

For flow conduits with mild slope and considerably large vertical curvatures the hydrostatic distribution of the pressure may be used for design proposes. However, for the spillway chutes actual pressure load over the steep slope beds with small vertical curvatures may differ from the hydrostatic pressure values. The differences in pressure load on curved bed chutes are mainly because of the ce...

Many thermohydraulic issues about the safety of light water reactors are related to complicated two-phase flow phenomena. In these phenomena, computational fluid dynamics (CFD) analysis using volume (VOF) method causes numerical diffusion generated by first-order upwind scheme used in convection term fraction equation. Thus, this study, we focused on an interface compression (IC) for such a VOF...

Spur dike is a common hydraulic structure, which is widely used in hydraulic engineering such as channel regulation, flood prevention and river diversion for preserving the desired water depth, deflecting the main current and protecting river banks. In actual operations, spur dikes exert influence on river system usually in the form of groups, and the flow field around spur dike group is compli...

there are different methods to reduce drag in high speed hulls. one of these methods is a change in the shape of the body by adding longitudinal side tunnels. in this paper it has been attempted to determine the influence of the tunnel height on hydrodynamic characteristics of the hull to achieving an optimum shape for the tunnel. to achieve this purpose, numerical simulation of the problem has...

Abstract In this research, a numerical investigation was carried out on the effect of obstacle presence water flow during dam-break in dry bed. The validity simulations confirmed after comparing results with experimental evidence. Rectangular, trapezoidal and triangle obstacles were simulated numerically to explain flow. Water surface tracking turbulent modeled using Volume Fluid (VOF) method s...

When a hydrogen or oxygen bubble is created on the surface of an electrode, micro-convective vortex flow due to Marangoni effect generated at bottom in contact with electrode. In order study such phenomenon numerically, it necessary be able simulate tension variations along liquid-gas interface, integrate mass transfer across interface from dissolved species present electrolyte gas phase, and t...

Volume-of-fluid (VOF) methods are popular for the direct numerical simulation of time-dependent viscous incompressible flow of multiple liquids. As in any numerical method, however, it has its weaknesses, namely, for flows in which the capillary force is the dominant physical mechanism. The lack of convergence with spatial refinement, or convergence to a solution that is slightly different from...