Performance of Submerged Ogee-Crest Weir Head-Discharge Relationships

CFD Modeling of Varied Flow Conditions Over an Ogee-Weir

“…Simulation results were compared with results from laboratory experiment conducted by Tullis et al [6,7] and the total upstream heads were reproduced with a mean absolute percentage error of 1.96%. After briefly overviewing the possible flow conditions during submergence, the numerical modeling of such events was conducted as well, as a main subject of the present paper.…”

“…In terms of submerged conditions, where the level of the tailwater exceeds the weir crest, the available empirical formulas to take account for the capacity reduction due to submergence are inapt [6,7], the effect is to be further investigated with experimental and numerical methods.…”

“…The numerical model was built up according to the experimental setup presented by [6,7], in order to make the simulation results well comparable with the laboratory measurements. A 510.9 mm high ogee-crested weir was used in the experiments and its shape was designed with the compound curve method [1] with a design head (H 0 ) of 233.5 mm which accordin g to the given discharge coefficient C f = 2.17 results in a specific design discharge (q d ) of 0.245 m 2 s -1 .…”

“…There are various semi-empirical methods available which take submergence into account [1,[3][4][5], however, laboratory experiments with an ogee-crested weir showed that these head-discharge relationships cannot provide reliable approximations, hence their applicability is to be questioned and further investigated [6,7]. The experimental results discussed in [6,7] give a thorough overview on the behavior of ogee-crested weirs under submerged conditions. The fact that the behavior of submerged weirs is basically determined by the geometry is duly noted, however, for the sake of simplicity only ogee type weirs will be concerned in the followings.…”

“…Based on the laboratory results presented by Tullis et al [6,7] Pedersen and Rüther conducted numerical experiments with the commercially available software Star-CCM+ to find out more about the mesh resolution dependency of a volume of fluids model for such cases [10]. Herein paper aims to present the numerical modeling of the same ogee-crested weir under various flow conditions in order to get a deeper understanding of the hydrodynamics of submergence and to show, that a modern freely available computational fluid dynamics (CFD) software with a more adequate free surface capturing approach could also mean a potential candidate for solving such hydraulic engineering related flow problems.…”