Prediction method for local scour by warmed cooling-water jets

This paper describes an investigation on a numerical prediction method to estimate local scour due to the cooling-water jets discharged from power stations. The method presented simulates the unsteady convection and diffusion of the warmed jets with a two-equation turbulence model within the calculation area being deformed by the local scour. The profile of the scoured sand bed is predicted by computing the amount of both the bed load and the suspended load in parallel with the simulation of the flow itself. The prediction method was applied to three kinds of experiments: a three-dimensional warm-jet experiment above a fixed bed, and two local-scour experiments carried out under two- and three-dimensional flows. The validity of the numerical prediction method was reasonably confirmed by these comparisons of results.