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Showing papers on "Volume of fluid method published in 1981"


Journal ArticleDOI
TL;DR: In this paper, the concept of a fractional volume of fluid (VOF) has been used to approximate free boundaries in finite-difference numerical simulations, which is shown to be more flexible and efficient than other methods for treating complicated free boundary configurations.

11,567 citations


Journal ArticleDOI
TL;DR: In this article, the axisymmetric flows with a two-layer density stratification are produced by releasing either a constant flux of fluid from a point source or a constant volume of fluid into a rotating environment with a different density.
Abstract: Axisymmetric flows with a two-layer density stratification are produced by releasing either a constant flux of fluid from a point source or a constant volume of fluid into a rotating environment with a different density. In both experiments the density interface intersects one horizontal boundary, forming a front. Transition to non-axisym-metric flow is observed and can be described by two parameters: θ, the square of the ratio of the internal Rossby radius of deformation to the horizontal length scale of the flow, and δ, the fraction of the total fluid depth occupied by the layer inside the front. For θ [Lt ] 1 and δ > 10−1 unstable disturbances obtain most of their energy from the potential energy of the flow, whilst for δ < 10−1 extraction of kinetic energy from the basic shear becomes the dominant driving mechanism. When the front intersects the free surface, n = 2 is the minimum azimuthal wavenumber for an unstable disturbance. At large amplitude of the growing waves, baroclinic and barotropic processes combine to form n vortex dipole structures which entrain buoyant fluid from the original vortex and propagate radially over the free surface. Vortices are also produced by the continuous release of fluid from a confined source at its own density level in a region of constant density gradient. As in the two-layer case the axisymmetric vortex grows to a critical size and then becomes unstable to a disturbance with wavenumber n = 2, producing, at large amplitude, two vortex pairs.

195 citations


Journal ArticleDOI
TL;DR: SOLA-VOF as discussed by the authors is based on the concept of a local average volume of fluid (VOF) and is embodied in a computer program for two-dimensional, transient fluid flow.
Abstract: There are numerous flow phenomena in pressure vessel and piping systems that involve the dynamics of free fluid surfaces. For example, fluid interfaces must be considered during the draining or filling of tanks, in the formation and collapse of vapor bubbles, and in seismically shaken vessels that are partially filled. To aid in the analysis of these types of flow phenomena, a new technique has been developed for the computation of complicated free-surface motions. This technique is based on the concept of a local average volume of fluid (VOF) and is embodied in a computer program for two-dimensional, transient fluid flow called SOLA-VOF. The basic approach used in the VOF technique is briefly described, and compared to other free-surface methods. Specific capabilities of the SOLA-VOF program are illustrated by generic examples of bubble growth and collapse, flows of immiscible fluid mixtures, and the confinement of spilled liquids.

46 citations


Book ChapterDOI
01 Jan 1981
TL;DR: The volume of fluid (VOF) technique as discussed by the authors is a simple and efficient means for numerically treating free boundaries embedded in a calculational mesh of Eulerian or Arbitrary-Lagrangian-Eulerian cells.
Abstract: The volume of fluid (VOF) technique is presented as a simple and efficient means for numerically treating free boundaries embedded in a calculational mesh of Eulerian or Arbitrary-Lagrangian-Eulerian cells. It is particularly useful because it uses a minimum of stored information, treats intersecting free boundaries automatically, and can be readily extended to three-dimensional calculations.

13 citations


Patent
Fehr Werner1
17 Dec 1981
TL;DR: In this paper, a method for controlling the volume of a fluid, e.g., air, moving through a duct system, including a ventilating system for a vehicle, is presented.
Abstract: Disclosed is a method for controlling the volume of a fluid, e.g., air, moving through a duct system, e.g., a ventilating system for a vehicle, comprising the steps of moving the fluid through an inlet of the duct system under dynamic pressure; conducting the fluid through the duct system by means of propulsion system driven by an electric motor, wherein the electric current drawn by said motor varies with changes in the dynamic pressure; and adjusting the amount of fluid admitted into the duct system in response to the current drawn by the motor and thus, also responsive to the dynamic pressure, this adjusting step thereby maintaining a constant volume of fluid moving through the air duct system. Also disclosed is an apparatus for carrying out this method.

6 citations


Book ChapterDOI
01 Jan 1981
TL;DR: In this paper, the authors restrict themselves to methods which are or have been applied in the field of air pollution modelling and apply them to a wide variety of fluid dynamical problems, all with different requirements.
Abstract: In recent years much attention has been paid to research of an accurate numerical integration technique of the advection equation. As the advection equation plays an important role in a wide variety of fluid dynamical problems, all with different requirements, it is unlike that there will he found an overall best and suitable method Therefore we shall restrict ourselves to methods which are or have been applied in the field of air pollution modelling.

4 citations


Journal ArticleDOI
TL;DR: In this paper, two numerical methods are basically used to calculate two-dimensional separationless steady flow of an inviscid compressible fluid through a turbine cascade, and it appears expedient to combine these methods and use the method of integral equations to specify the initial flow field and automated construction of the difference mesh on which the calculation is then continued by the stabilization method.
Abstract: Two numerical methods are basically used to calculate two-dimensional separationless steady flow of an inviscid compressible fluid through a turbine cascade. For the subsonic flow over the profile, the method of integral equations [1] is used. It has a high accuracy in the region of the entry edge because of the concentration on it of the computational points, and for an incompressible fluid it requires comparatively little computer time compared with other methods. For all velocities, the stabilization method [2] is used successfully. Application of a finite-difference through-computation scheme makes it possible to carry out calculations without explicit separation of singularities (discontinuities) in the flow. Shock waves are obtained in this case as narrow regions (a few cells of the difference mesh) with large gradients of the parameters. In the existing variant of the method [3], the computational mesh is constructed manually, which entails much time and requires considerable experience of such work. It appears expedient to combine these methods and use the method of integral equations to specify the initial flow field and an automated construction of the difference mesh on which the calculation is then continued by the stabilization method. In the greater part of the flow, the difference mesh is constructed from the equipotentials and streamlines of the flow of an incompressible fluid. This ensures a cell shape which is nearly orthogonal, and this shortens the computing time and raises the accuracy of the results in the stabilization method.