By recording parameters such as velocity and volume fraction by contour plots or plane, a CFD model enables to analyse flow patterns in the model, such as free-surface vortices A free-surface vortex, a common problem may indeed be observed in a variety of submerged water intakes, notably shallow basins and low head intakes. These FSVs are likely to form an air-core vortex, eventually entrapping detritus and air pockets in the water intake system and causing further vibration and damage to the downstream turbine. When paired with a high velocity, the formation of vortices in the system been known to produce hydraulic transients, which cause unwanted operation or pressure changes. The model of the 1:100 scale dam reservoir was generated, computationally meshed, and modelled in FLUENT under ANSYS 2019 R3 at two different water levels to observe the FSV formations. To mitigate those FSV formations, anti-vortex plates with two distinct plates—square and wedge—were used. From the findings square plates outperform wedge plates because square it lowers the speed of a fast-flowing fluid and reduces it into a laminar flow rather of a turbulent flow, which benefits vortex class deterioration. Data from the simulation and experimental shows a strong agreement in terms of velocity at outlet 1 from both water levels with relative errors of 3.0% and 14.1% respectively

Water flowing over a spillway has a very high kinetic energy because of the conversion of the entire potential energy to kinetic energy. This circumstance results in damage or significant erosion at the toes of the spillways, weir bed, and downstream of a river. To solve this problem, the water flow velocity must be minimised. Physical modelling was implemented to this conundrum in order to modify the current energy dissipating structure, the stilling basin, to enhance energy dissipation as much as achievable by downstream velocity reduction. Baffle blocks were adopted as the modification in this study because these are widely used to stabilize the jumps, shorten its length, and maximize energy dissipation. A selection of baffle arrangements was evaluated by positioning them in the stilling basin’s mid-span to identify the most effective outcome in minimizing downstream velocity. From the findings, it was clearly shown the arrangement of baffles blocks at the stilling basin impacts velocity reduction in various discharge cases. The formation of cross-waves was also assessed at the discharge channel at every discharge value with its relative distance from the sump and the width of the channel prior to the site. For discharge situations of 70.0 L/s and 100.0 L/s, modifications to the Type II stilling basin were recommended. Furthermore, constriction, expansion, or curvature should be avoided in chute spillways identical to the dam spillway to limit cross-wave generation and other unfavourable flow behaviours