DETACHED EDDY SIMULATION OF HYDRAULIC CHARACTERISTICS ALONG THE SIDE-WALL AFTER A NEW ARRANGEMENT-SCHEME OF THE SUDDEN LATERAL ENLARGEMENT AND THE VERTICAL DROP

In order to study the cavitation damage in a side-wall when a sudden lateral enlargement and a vertical drop are imposed at the radial gate, a new arrangement-scheme is proposed, where the sudden lateral enlargement and the vertical drop can be imposed at the outlet of the gate chamber. The hydraulic characteristics along the side-wall are simulated by the detached eddy simulation and the Volume Of Fluid (VOF) method. The numerical results agree well with those of experiment. The experimental and numerical results show that the flow condition is smooth with only a weak water-wing appearing behind the lateral cavity, and the length of the lateral cavity becomes longer and is mainly affected by the size of the lateral enlargement and the zone of negative pressure after the water impacts the side-wall would disappear. The hydraulic characteristics of the new arrangement-scheme are beneficial to the prevention of the cavitation damage in the side-wall and the Detached Eddy Simulation (DES) with the VOF method can well predict the hydraulic characteristics after the new arrangement-scheme of the sudden lateral enlargement and the vertical drop.