Prediction of the Transom Flow Regime with Viscous Free Surface Computations

Abstract

A steady free-surface fitting RANS method is used to accurately and efficiently compute the flow near a ship"s transom. The chosen block topology is very well suited for the prediction of such flows: viscous free-surface flow solutions have been obtained for all transom flow regimes (from completely dry, partly wetted to completely wetted) and the agreement with available measurements is good. We will show that scale effects on the flow aft of the transom can be significant: they can affect the wave length and wave amplitude aft of the transom, and can even change the transom flow regime from partly wetted to completely dry.

Full-scale ship stern wave with the modelled and resolved turbulence including the hull roughness effect

“…The scaling effects relate commonly to the fluid phenomena, which depend on the Reynolds number. Some examples are the boundary layer thickness or wave breaking that are viscous scale-dependent phenomena, which have already been extensively investigated [12,13,14,15,16,17,18,19].…”