A Computational Fluid Dynamics Simulation Model of Sediment Deposition in a Storage Reservoir Subject to Water Withdrawal

Abstract

Siltation is one of the most common problems in storage projects and attached structures around the world, due to its effects on a project’s life span and operational efficiency. A three-dimensional computational fluid dynamics (CFD) model was applied to study the flow and sediment deposition in a multipurpose reservoir (Mosul Dam Reservoir, Iraq) subject to water withdrawal via a pumping station. A suitable control code was developed for the sediment simulation in intakes with multiblock option (SSIIM) model, in order to simulate a study case and achieve the study aims. The measured total deposited load in the reservoir after 25 years of operation and the measured sediment load concentration at different points near the pumping station intake were considered to validate the model results. The sediment load concentrations at several points near the water intake were compared; the percent bias (PBIAS) value was 3.6%, while the t-test value was 0.43, less than the tabulated value, indicating fair model performance. The model sensitivity to grid size and time steps was also tested. Four selected bed level sections along the reservoir were compared with the simulated values and indicate good performance of the model in predicting the sediment load deposition. The PBIAS ranged between 4.8% and 80.7%, and the paired t-test values indicate good model performance for most of the sections.

Experiments of Geometric Shape of Sediment Trap Rectangular and Vortex Settling Desilting Basin

“…For flows with a clear separation between one phase and another, the Volume of Fluid (VoF) model is used. This model is also relatively simple and efficient compared to eulerian or mixture [14].…”

“…Surface: At the top of the domain, the effects of wall friction are removed to represent atmospheric air, and d). Outlet: The outlet section is a pressure outlet representing the flow's "exit" [14]. Computational Fluid Dynamics (CFD) is the art of transforming fluid dynamics set equations in the form of integrals and derivatives into discrete algebraic forms, which a computer can solve to obtain the values of the flow field at a particular discrete point or time [19].…”

“…Computational Fluid Dynamics (CFD) is the art of transforming fluid dynamics set equations in the form of integrals and derivatives into discrete algebraic forms, which a computer can solve to obtain the values of the flow field at a particular discrete point or time [19]. As for the regulatory equations in fluid dynamics: the continuity equation, the momentum equation and the energy equation [13], [14]. Here are the equations used in CFDs, continuity equation of integral forms:…”

Assessing the Impact of Auxiliary Kandar Dam Construction on Effective Lifespan of Main Kandar Dam Reservoir: A Case Study from District Kohat, Khyber Pakhtunkhwa, Pakistan"

“…The wavelet arti cial neural network (WANN) model emerged as the most accurate predictor for suspended sediment load (SSL) (Zeyneb et al 2022). Mohammad et al (2020) demonstrated through the Sediment Simulation in Intakes with Multi-block option (SSIIM) model how sediment distribution re ects changes in bed level and water levels. Soil erosion, in uenced by sediment load and drainage areas, poses signi cant environmental and societal challenges.…”

Submerged Wall Instead of a Penstock Shutoff Valve—Alternative Protection as Part of a Refurbishment

“…Strategies should target the reduction of the incoming amount of sediment and can include the installation of a sediment bypass tunnel [14]. In the worst case scenario, the adaptation of the intake structure is a temporary solution to maintain the HPP in operation [15][16][17]. Ongoing modernisation efforts also allow the reduction of the environmental impact of HPP, which also includes the development of new fish protection concepts [18][19][20].…”