Volume of fluid method

About: Volume of fluid method is a research topic. Over the lifetime, 5338 publications have been published within this topic receiving 116760 citations.

A numerical method for solving three-dimensional generalized Newtonian free surface flows

Abstract: This work presents a numerical technique for solving three-dimensional generalized Newtonian free surface flows. It is an extension to three dimensions of the technique introduced by Tome et al. [M.F. Tome, B. Duffy, S. McKee, A numerical technique for solving unsteady non-Newtonian free surface flows, J. Non-Newtonian Fluid Mech. 62 (1996) 9–34] but additionally includes many other features. The governing equations are solved by a finite difference method on a staggered grid. It uses marker particles to describe the fluid; these particles provide the location and visualization of the fluid free surface. As currently implemented, the present method can simulate generalized Newtonian flow in which the viscosity is modelled using the Cross model. The numerical technique presented in this paper is validated by using exact solutions for the flow of a Cross model fluid inside a pipe and convergence is demonstrated by means of grid refinement for the problem of a spreading drop. Numerical results showing the flow of a generalized Newtonian fluid jet impinging onto a flat surface and that of a jet buckling are given.

Dispensing method and apparatus for dispensing very small quantities of fluid

Abstract: A fluid dispensing system and method includes a pump to aspirate and expel sample fluid, a fluid dispensing tip, and a metering station. The fluid dispensing tip includes a working fluid and an air gap where the air gap separates the working fluid from the sample fluid. The metering station receives a drop of sample fluid that is at least twice as large as the predetermined volume to ultimately be dispensed. The fluid dispensing tip then withdraws the predetermined volume of fluid from the sample fluid. Precise volumes are ascertained by prior knowledge of the geometry of the fluid dispensing tip and by using an imaging device to monitor an interface of either the sample fluid or working fluid with the air gap within the fluid dispensing tip. The system and method are capable of accurately dispensing very small volumes of sample fluid on the order of 10 picoliters. In addition, the system and method do not require large volumes of sample fluid to prime a pump mechanism.

Numerical Simulation of Confluence Flow in Open Channel with Dynamic Meshes Techniques

Abstract: Due to the interaction between branch flow and main stream at confluence zone in open channel, the water level of free surface often varies dramatically. In three dimensional simulations of confluence flow, multi-phase models are usually adopted in treating the free-surface boundary, for example, the Volume of Fluid model. The major dilemma for adopting multi-phase modes is that the method consumes more time and computation resources. In this study, the new mesh technique, the dynamic meshes, is adopted to track the position of free surface. The simulation results show that simulation adopting dynamic meshes converges rapidly and is in good agreement with the experimental data. In addition, simulations and comparisons of different turbulence models coupled with dynamic meshes, rigid lid, or the Volume of Fluid method are carried out to investigate the impact by tracing the free-surface boundary. The simulated position of free surface, velocity distribution, and vector field are all compared to the data co...