Development of a large-eddy simulation open channel code

Describes further development of a 3D finite difference code written to mod el turbulent flows in an open channel with a moving free surface. The code has been developed so that the computational domain can have side-walls and /or periodic directions and that the flow may also be buoyancy driven. Eith er a full simulation or large eddy simulation (LES) of the turbulence can b e performed. Results are presented of a simulation of periodic streamwise f low in an open channel with parallel side-walls and also of a thermal jet i nto an open tank. Both simulations were carried out on a UNIX workstation u sing resolutions that enable the results to be viewed within an "engineerin g context". The LES application demands numerical approximations which cons erve mass, momentum and total energy with high precision, and which permits wave motion with very little numerical dispersion or dissipation. The free surface is tracked using a split-merge technique which combines the volume of fluid (VOF) and height function methods in a way that is conservative.