VOF Method with High-order STACS Scheme and Numerical Simulation of Gas-liquid Interfacial Flows
|School||East China University of Science and Technology|
|Course||Fluid Machinery and Engineering|
|Keywords||high-order STACS scheme VOF method single bubbles vertical falling film numerical simulation|
Conjugate and deformable gas-liquid interface contained in rising bubbles and/or falling liquid films are widely occurred in the nature and procedures.Because the interface is deformable and the surface tension is not able to be calculated easily,the study of numerically simulating the gas-liquid interface,with high-order schemes employed for improving the accuracy and the sharpness of the interface,has become an important topic in the CFD.In this paper,the analysis is based on the nonstaggered SIMPLE method,which is in the Finite Volume Form.High-order STACS scheme is used for discretization,while the deferred correction method is employed to stablize the calculation.The surface tension is added into momentum equation in the form of a body force.The governing equations of the VOF method including the STACS scheme and surface tension are successfully implemented into a FORTRAN code.The movement of a single rising bubble is a basic problem of gas-liquid two-phase flows. Bubble deformation is determined by buoyancy, gravity,viscous force,and surface tension.The high-order STACS scheme and the VOF method are tested by calculating the deformation and movement of single bubbles rising in the water. The results indicate that continuity and slickness of the bubble surface are better simulated by high-order STACS scheme than by either the high-order SMART scheme and the FLUENT,as compared with the published results in literatures.Numerical simulation of a vertically falling film of highly viscous fluids through a single hole element has been carried out. Fluidity,contraction of liquid film for the whole falling film flow and film area in a selected extent are studied.The hydro-dynamic behaviour of falling film of highly viscous fluids and the selection of single hole falling film element are discussed.