Numerical Study on the Hydrodynamic Characteristics of Biofouled
Full-Scale Net Cage |
| |
| Authors: | BI Chun-wei ZHAO Yun-peng and DONG Guo-hai |
| |
| Institution: | State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology,
Dalian 116024, China;State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology,
Dalian 116024, China;State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology,
Dalian 116024, China |
| |
| Abstract: | The effect of biofouling on the hydrodynamic characteristics of the net cage is of particular interest as biofouled nettings can significantly reduce flow of well-oxygenated water reaching the stocked fish. For computational efficiency, the porous-media fluid model is proposed to simulate flow through the biofouled plane net and full-scale net cage. The porous coefficients of the porous-media fluid model can be determined from the quadratic-function relationship between the hydrodynamic forces on a plane net and the flow velocity using the least squares method. In this study, drag forces on and flow fields around five plane nets with different levels of biofouling are calculated by use of the proposed model. The numerical results are compared with the experimental data of Swift et al. (2006) and the effectiveness of the numerical model is presented. On that basis, flow through full-scale net cages with the same level of biofouling as the tested plane nets are modeled. The flow fields inside and around biofouled net cages are analyzed and the drag force acting on a net cage is estimated by a control volume analysis method. According to the numerical results, empirical formulas of reduction in flow velocity and load on a net cage are derived as function of drag coefficient of the corresponding biofouled netting. |
| |
| Keywords: | net cage biofouling drag force flow field numerical simulation |
|
| 点击此处可从《海洋工程》浏览原始摘要信息 |
| 点击此处可从《海洋工程》下载免费的PDF全文 |
|
