Water Level Variation along a Submerged Lateral Weir

Cross flow over a submerged weir between two parallel cooling water intake flumes for a power plant is analyzed by employing spatially varied flow formulations to account for flow and submergence variability. A lateral weir is used to equalize and distribute flow between two cooling tower basins that discharge into separate intake flumes that have a common wall. The crest of the lateral weir is selected such that the desired amount of flow is diverted from one basin to the other. At the lateral weir, flow in the supplying flume decreases in the downstream direction whereas flow in the receiving flume increases by the same amount. The water level difference between the supplying and the receiving flumes is relatively small that the lateral weir operates under submerged conditions. The submergence of the lateral weir is not constant along the length of the weir but varies depending on the water level within the flumes. Therefore, a numerical technique was developed to compute the water level profile along the lateral weir iteratively by accounting the dependence of weir coefficient on the level of submergence. The method developed was found to be useful in solving flow problems related to submerged lateral/side weirs between two channels/flumes.