Free surface (fluid mechanics)
Free surface (engl. Free surface ) referred to in the computational fluid dynamics or the fluid dynamics , the interface between a gas and a liquid .
The reason for labeling with the term "free" is the large difference in density between the gas and the liquid (the density ratio of water to air is 1000). The low density of the gas means that its inertia force can generally be ignored in comparison with that of the liquid, so that the liquid movement is "independent" or "free" of the inertia force of the gas.
There are numerous numerical calculation methods to calculate free surface:
- Marker-and-Cell / MAC method according to Harlow and Welch (oldest calculation method, published in 1965)
- Volume of Fluid / VOF method , published by Nichols and Hirt
- Arbitrary Lagrangian Eulerian / ALE method.
literature
- Francis H. Harlow, J. Eddie Welch: Numerical Calculation of Time-Dependent Viscous Incompressible Flow . In: Physics of Fluids , Vol. 8 (1965), p. 2182, ISSN 0031-9171 .
- Cyril W. Hirt, B. Nichols: Volume of fluid method for the dynamics of free boundaries . In: Journal of Computational Physics , Vol. 39 (1981), pp. 201-225, ISSN 0021-9991 .
- Cyril W. Hirt, JL Cook, T. Daniel Butler: A Lagrangian Method for Calculating the Dynamics of an Incompressible Fluid with Free Surface . In: Journal of Computational Physics , Vol. 5 (1970), p. 103, ISSN 0021-9991 .
- Cyril W. Hirt, Anthony A. Amsden, JL Cook: An Arbitrary Lagrangian-Eulerian Computing Method for all Flow Speeds . In: Journal of Computational Physics , Vol. 14 (1974), p. 227, ISSN 0021-9991 .