Author(s): Jungseok Ho; Hong Koo Yeo; Julie Coonrod; Won-Sik Ahn
Linked Author(s):
Keywords: Groyne; Recirculation; Velocity distribution; Numerical models; Computational fluid dynamics technique
Abstract: Numerical modeling for single groyne in a rectangular section flume was developed to investigate flow pattern changes and to find the best performing installation interval. A threedimensional computational fluid dynamics model was built to simulate the flow properties near the groyne including the groyne tip velocity and the flow separation length. To evaluate hydraulic influences on the tip velocity and the separation length, four different ratio of groyne length to channel width and five various porous groynes were simulated over varied approach velocity in this study. Permeability of the groyne was reproduced by changing the gap between the cylinders. The approach water depths and the approach velocity acquired from the physical model were treated as the boundary conditions for the numerical model. Computed groyne tip velocity, the separation length, and two-dimensional velocity vector were compared with the physical model measurements for validation of the numerical model. The numerical model computations showed very positive agreements with the physical model measurements. Relative error analysis showed that the numerical model agreed within 5 % with the physical model up to 40 % of the groyne permeability. The relationship of the ratio of the computed separation length to groyne length with Froude number was presented and compared with the empirical equation suggested from the physical model. It was found that the numerical model can complement the physical model. The validated numerical model will be used to investigate the effects of the groyne installation angle, series of groynes, and curved channel application for future studies.
Year: 2007