The aim of the present study was to investigate the influence of channel bed geometry (i.e., width \(B\) , slope \(S\) , bottom length \(L\) , and height \(H\) of upstream and downstream apron sections) on the discharge capacity and resultant electricity generation of a tidal range power plant. The CFD results showed that the apron width and height significantly affected the discharge capability of sluice passage, while the effects of apron slope and bottom length can be negligible. The mean discharge coefficients for \({B \mathord{\left/ {\vphantom {B {B_{t} }}} \right. \kern-0pt} {B_{t} }}\) = 1, 3 and 5 (where \(B_{t}\) is the sluice passage width) were 0.77, 0.71 and 0.66, respectively, while 0.79, 0.77 and 0.69 for \(H\) / \(B_{t}\) = 0, 0.25 and 0.5, respectively, indicating significant decreases in the discharge capability with increasing \({B \mathord{\left/ {\vphantom {B {B_{t} }}} \right. \kern-0pt} {B_{t} }}\) and \(H\) / \(B_{t}\) . From the results of 0-D modelling in the case study of the Taedong Bay barrage, the DPR Korea, it is shown that the reduction in the discharge capability of sluice passage resulted in the decrease in the electricity production. The annual power output for the Taedong barrage decreased significantly from 476.6 to 457.9 GWh with increasing \(H\) / \(B_{t}\) , showing the largest reduction of about 4.1% for the condition of \(H\) / \(B_{t}\) = 0.5. It can be concluded that the present results will help engineers and scientists to propose an optimal shape for apron section to enhance the discharge capability of sluice passage (and the resultant power output) of tidal range power plants.
