Discussion of 'Flow over a stepped chute with and without macro-roughness elements'

摘要

The author, Mehmet Ali Kokpinar, presents results of air entrainment characteristics for high-velocity aerated flows over stepped chutes with macro-roughness elements. He obtained this data during his post-doctoral visit from September 2000 to February 2001 at the Laboratory of Hydraulic Constructions (LCH) of the Swiss Federal Institute of Technology in Lausanne (EPFL). The discussers are somewhat surprised to see that the author did not present the context of his work and the references to the research performed at the host institute LCH-EPFL, since 2001. Therefore, before discussing the experimental results of the author, the discussers would first like to outline the participation of the author in the research activities that were ongoing during his visit. During his stay at the host institute, the author worked in close collaboration with the discussers, especially with Stephanie Andre who was performing her doctoral research entitled High velocity aerated flows on stepped chutes with macro-roughness elements (Andre 2004). The Ph.D. research consisted of comprehensive experimental and numerical studies with the purpose of extending the knowledge base on aerated flows over macro-roughness (aerated and macro-turbulent flow structures, flow characteristics such as regimes, depths, air concentration and velocity distributions, and hydrodynamic forces) and analyzing in detail the energy dissipation process, due to macro-roughness. Furthermore, preliminary guidelines for the optimization of stepped macro-roughness overlays to increase the flood safety of dams were provided.