Session
Session 1 2022
Start Date
10-26-2022 12:00 AM
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Das B., Ahmad, Z., and Sharma, P.K. (2022). "Experimental and Numerical Investigation on Critical Submergence for Square Water Intakes" in "9th IAHR International Symposium on Hydraulic Structures (9th ISHS)". Proceedings of the 9th IAHR International Symposium on Hydraulic Structures – 9th ISHS, 24-27 October 2022, IIT Roorkee, Roorkee, India. Palermo, Ahmad, Crookston, and Erpicum Editors. Utah State University, Logan, Utah, USA, 10 pages (DOI: 10.26077/817c-13b1) (ISBN 978-1-958416-07-5).
Abstract
Critical submergence for square water intakes in an open channel flow has been investigated experimentally and numerically in this paper. The depth of water at which the tail of a free surface vortex core just reaches the tip of an intake causing air entrainment is referred to as critical submergence. The formation of an air-entraining vortex in the vicinity of an intake is considered to be a severe problem for pumps. Experiments were conducted in a concrete flume of 9.47 m length, 0.5 m wide, and 0.6 m deep with an intake of size 0.04 m×0.04 m under uniform flow for different flow conditions. A three-dimensional Multiphase CFD Model was also developed for simulating critical submergence for the intakes. SST k-ω turbulence model together with the volume of fluid (VOF) two-phase (water-air) model were used to simulate the flow field in the water intake system. In the CFD simulation study, critical submergence was identified using phase volume fraction analysis and free surface streamline analysis. From both experimental and numerical studies, it is found that the approach flow Froude number and intake flow Froude number play an important role for estimating critical submergence depth. The critical submergence increases with an increase in intake Froude number and decreases with an increase in approach Froude number for a square Intake. The outcomes of the CFD simulation were validated with experimental data.
Experimental and Numerical Investigation on Critical Submergence for Square Water Intakes
Critical submergence for square water intakes in an open channel flow has been investigated experimentally and numerically in this paper. The depth of water at which the tail of a free surface vortex core just reaches the tip of an intake causing air entrainment is referred to as critical submergence. The formation of an air-entraining vortex in the vicinity of an intake is considered to be a severe problem for pumps. Experiments were conducted in a concrete flume of 9.47 m length, 0.5 m wide, and 0.6 m deep with an intake of size 0.04 m×0.04 m under uniform flow for different flow conditions. A three-dimensional Multiphase CFD Model was also developed for simulating critical submergence for the intakes. SST k-ω turbulence model together with the volume of fluid (VOF) two-phase (water-air) model were used to simulate the flow field in the water intake system. In the CFD simulation study, critical submergence was identified using phase volume fraction analysis and free surface streamline analysis. From both experimental and numerical studies, it is found that the approach flow Froude number and intake flow Froude number play an important role for estimating critical submergence depth. The critical submergence increases with an increase in intake Froude number and decreases with an increase in approach Froude number for a square Intake. The outcomes of the CFD simulation were validated with experimental data.