In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodyna...In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodynamics coefficients of the vessel are calculated by using a 3D diffraction/radiation panel program. First- and second-order wave forces are included in the calculations. Morison equation is used to compute the drag force on line elements representing the net. Drag coefficients are determined at every time step in the simulation considering the relative normal velocity between the structural elements and the fluid flow. The dynamic response of the coupled system is analyzed for various environments and net materials. The results of the study show the effects of solidity ratio of the net and vertical positions of the cage on the overall dynamic response of the system, confirming the viability of this type of configuration for future development of offshore aquaculture in deep waters.展开更多
Since the fracture property of corn stalk determines the difficulty for corn to fall off,it is of great significance to study the fracture law of the corn stalk with high water content and explore the corn threshing m...Since the fracture property of corn stalk determines the difficulty for corn to fall off,it is of great significance to study the fracture law of the corn stalk with high water content and explore the corn threshing method without causing great damage.Taking two varieties of corn as the research object,this study carried out single and multi-angle corn stalk fracture tests to explore the changes in the linkage between stalk and corn kernel at different positions as well as under different application modes and angles.The results showed that the force required for radial stretching was the greatest.Moreover,the fracture mechanics model of corn stalk was established to measure the fracture toughness of corn stalk.The peak value of critical load P_(Q) load displacement curve(F_(MAX))was indicated.Based on the fractal theory,the fractal characteristics of the fracture surface of the stalk at different positions of the ear were analyzed,and the fractal dimension was calculated using the islet method.The findings indicated that the larger the fractal dimension of the fracture surface on the corn stalk,the more energy consumed in the fracture of corn stalk.These findings can be further utilized to explore the performance of corn kernel and reveal the fracture rule of corn kernel and stalk to identify the optimal form of force to make corn kernels fall off the corn cob and provide the theoretical basis for reducing the loss caused in the falling process of corn kernel.展开更多
基金Kampachi Farms LLC for their support to complete this work and for all the technical information provided to complete the numerical model
文摘In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodynamics coefficients of the vessel are calculated by using a 3D diffraction/radiation panel program. First- and second-order wave forces are included in the calculations. Morison equation is used to compute the drag force on line elements representing the net. Drag coefficients are determined at every time step in the simulation considering the relative normal velocity between the structural elements and the fluid flow. The dynamic response of the coupled system is analyzed for various environments and net materials. The results of the study show the effects of solidity ratio of the net and vertical positions of the cage on the overall dynamic response of the system, confirming the viability of this type of configuration for future development of offshore aquaculture in deep waters.
基金supported by the National Natural Science Foundation of China(Grant No.52275245)Henan Science and Technology Research Program(Grant No.222103810041).
文摘Since the fracture property of corn stalk determines the difficulty for corn to fall off,it is of great significance to study the fracture law of the corn stalk with high water content and explore the corn threshing method without causing great damage.Taking two varieties of corn as the research object,this study carried out single and multi-angle corn stalk fracture tests to explore the changes in the linkage between stalk and corn kernel at different positions as well as under different application modes and angles.The results showed that the force required for radial stretching was the greatest.Moreover,the fracture mechanics model of corn stalk was established to measure the fracture toughness of corn stalk.The peak value of critical load P_(Q) load displacement curve(F_(MAX))was indicated.Based on the fractal theory,the fractal characteristics of the fracture surface of the stalk at different positions of the ear were analyzed,and the fractal dimension was calculated using the islet method.The findings indicated that the larger the fractal dimension of the fracture surface on the corn stalk,the more energy consumed in the fracture of corn stalk.These findings can be further utilized to explore the performance of corn kernel and reveal the fracture rule of corn kernel and stalk to identify the optimal form of force to make corn kernels fall off the corn cob and provide the theoretical basis for reducing the loss caused in the falling process of corn kernel.
