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Abstract: A numerical approach is proposed to simulate the interaction between flow and flexible nets in steady current. The numerical approach is based on the joint use of the porous-media model and the lumped-mass model. The configuration of flexible nets can be simulated using the lumped-mass model and the flow field around fishing nets can be simulated using the porous-media model. Using an appropriate iterative scheme, the fluid–structure interaction problem can be solved and the steady flow field around flexible nets can be obtained. In order to validate the numerical models, the numerical results were compared with the data obtained from corresponding physical model tests. The comparisons show that the numerical results are in good agreement with the experimental data. Using the proposed numerical approach, this paper presents the flow field around a single flexible net and two flexible nets with a spacing distance. Both the configuration of the flexible nets and the flow velocity results are in accordance with those of the corresponding physical model tests. [Copyright &y& Elsevier]

Based on the finite volume method, adopting the movement border as a wave generator, a twodimensional numerical wave flume is established. The volume of fluid (VOF) method is used to track the wave surface. After comparison of the numerical results with the theoretical results, the accuracy of the numerical wave flume is verified. In the numerical simulation, the net panel is simplified as porous media entirely. The coefficients of the porous media are determined by the least squares method. In this way, the porous media model will have the same pressure drop as the net panel. In order to validate the numerical model, the numerical results were compared with the data obtained from corresponding physical model tests, and the numerical results and the corresponding experimental data show reasonably good agreement. Using the proposed numerical approach, this paper presents wave propagation through a net panel with different net solidities, different attack angles as well as two nets with different spacing distances. The impacts of the wave height and wavelength on the wave propagation through the net panel are also discussed. [ABSTRACT FROM AUTHOR]

Abstract: Numerical simulation is performed to analyze the hydrodynamic response of a net cage and submerged mooring grid system exposed to waves and current. A series of experiments are conducted to validate the numerical model of net cage and grid mooring system. The numerical results of this model correspond with those obtained from experimental observations. Then, the numerical simulation of a multi-cage and mooring system under the action of waves combined with current is conducted. The influence of waves and current directions and the length of grid lines on the cage responses are discussed. The twin mooring system and the orthogonal mooring system are compared. Results show that for the orthogonal mooring system, the maximum tension force on the anchor line of the four-cage system is less than four times of that of the single-cage system, when both waves and current travel along the x-axis. The minimum net cage volume holding coefficient of the single-cage system is smaller than that of the four-cage system. The amplitude of the mooring line tension force for the twin mooring system is larger than the orthogonal mooring system. [Copyright &y& Elsevier]

Abstract: Fluid flow uniformity is an important index in many research fields including artificial environment in the room. In order to facilitate quantifying the multi-section flow uniformity directly by simulation results and to simplify the computation process, a correlation based on area-weighted average velocities and mass-weighted average velocities is proposed in this paper. To test the proposed approach to quantifying flow uniformity, the correlation is applied in two studies – one based on assumed velocity distribution, another based on the simulated velocity distribution – in comparison with two existing formulae from prior studies. The results show that the evaluation results of the proposed correlation are in complete agreement with that of the two formulae from prior studies in the overall trend. The correlation may be used in a wide range of contexts without strict requirement for uniformity to quantify the fluid uniformity in a relatively simple manner. [Copyright &y& Elsevier]