| Title |
Numerical Modeling of Wave-Type Turbulent Flow on a Stepped Weir |
| Authors |
백중철(Paik, Joongcheol) ; 이남주(Lee, Nam-Ju) ; 윤영호(Yoon, Young Ho) |
| DOI |
https://doi.org/10.12652/Ksce.2017.37.3.0575 |
| Keywords |
계단형 보;파형흐름;난류흐름;도수;수치모의 Stepped weir;Wave-type flow;Turbulent flow;Hydraulic jump;Numerical modeling |
| Abstract |
Various types of flow patterns around the stepped weir and spillway, such as the skimming flow over such structures and the wave-type flow with a standing undular hydraulic jump and roller downstream of the structures, are developed in open channels. Unsteady three-dimensional numerical simulations are carried out using a hybrid RANS-LES turbulence modeling approach and the volume of fluid method for resolving free surface fluctuations to represent the turbulent flow including the skimming flow and wave-type flow over a stepped weir installed in a rectangular channel. The comparison of numerical results with an existing experimental measurement reveals that the present numerical simulations reasonably well reproduce the turbulent flow passing the stepped weir, in terms of time-averaged velocity profiles at selected locations downstream of the weir, flow topology characterized by the wave-type and skimming flows, the maximum height and length of the standing wave and the length of reattachment of recirculating zone. The numerical result further elucidates the distinct flow behaviors of the wave-type and skimming flow by presenting instantaneous intense variations of free surface and velocity vectors, the distributions of Reynolds shear stress and turbulent kinetic energy and three-dimensional complex features of coherent structures and total pressure distribution. |