Abstract
In computational fluid dynamics, various boundary conditions are used, and some of them have required special treatments. Free surfaces, density interfaces, and open boundaries encountered in hydraulic numerical analysis are those examples. On the basis of a deformable-cell method, in which cells dividing the incompressible fluid can deform according to the movingboundaries, most boundary conditions are considered on a “generalized boundary equation, ” and they can be treated in a unified manner. The density stratified shear flow at a river mouth is simulated nu-merically by this method, and each boundary is shown to behave as expected.
