Numerical simulation and piv study of unsteady flow around hollow cube artificial reef with free water surface

Abstract

There are studies of the flow fields of artificial reefs by comprehensive 3D numerical investigations in the literature. In this paper, the flow fields within and around a hollow cube artificial reef are investigated. The complicated three-dimensional unsteady turbulent flow simulation is carried out on the basis of Navier-Stokes solver. A one-phase model is embedded with a renormalization group (RNG) k-ε turbulence model and sloved using the method of SIMPLEC algorithm. Free water surface is modeled as a wall boundary condition with zero shear force. The flow fields are solved by employing fmite volume method (FVM) simulation. In order to validate the simulated results, non-invasive particle image velocimetry (PIV) measurements are conducted to measure the flow patterns. The comparisons shows a good agreement between the numerical and experimental results concerning the scales and characteristics of the major current arising from the artificial reef. Based on the experimental verification, the effects of variation in reef height on the flow field are simulated and analyzed. Unit artificial reef effect is also calculated and analyzed. According to the numerical results, a better unit artificial reef effect is obtained when the ratio of reef height to water-depth is in the vicinity of 0.2. © 2012 2012 Taylor and Francis Group LLC.