Time evolution of the scour induced by a ski jump jet

Abstract

Scour studies are often made at the equilibrium stage when the scour hole is stabilized and no more changes in the scour geometry occur. However, studying the scour time evolution is critical to better understand the erosion process and the main factors that control it in the short and long terms. Scour is a destructive process, therefore, in the absence of non-intrusive and real-time measurement techniques, an experimental analysis of time evolution of scour can be a time-consuming process as, for each considered instant, detailed measurements of the bed geometry must be taken. In this paper, two different strategies are applied to analyse the scour time evolution. Their results are compared and discussed. From the obtained experimental results, empirical relations between different variables were proposed. Further analysis provided scale relationships to adimensionalize the time evolution profiles. To measure the scour geometry, a structure from motion technique is employed.