Abstract
The hydraulic characteristic of submerged overflow is not fully solved as compared with perfect overflow. Moreover, in the research on a weir, the hydraulic model test is conducted in many cases. However, if the flow over a weir can be reproduced in sufficient accuracy by numerical analysis, it will be able to contribute to the elucidation of its hydraulic characteristic greatly. Then, in this research, numerical analysis of the submerged over flow on trapezoidal weir is performed. Consequently, the flow change by the difference in Ht/Ho is in good agreement with experimental measurements (Ho: water depth at upstream of weir, Ht: water depth at downstream of weir, both from weir crest). Additionally, by not disregarding approaching velocity head and evaluating discharge from the channel floor to the water surface, the possibility of deriving the discharge formula which can be applied when Ht/Ho is close to 100% is shown.
