To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary for...To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary force correction is used to save the computational cost and memory,and the momentum forcing is described by a simple direct force formula without complicated integral calculation when the velocity correction at the boundary node is determined.With the presented flow solver,the hydrodynamic interaction between the fish-induced dynamic stall vortices and the incoming vortices in unsteady flow is analyzed.Numerical simulation results unveil the mechanism of fish exploiting vortices to enhance their own hydrodynamic performances.The superior swimming performances originate from the relative movement between the“merged vortex”and the locomotion of the fishtail,which is controlled by the phase difference.Formation conditions of the“merged vortex”become the key factor for fish to exploit vortices to improve their swimming performance.We further discuss the effect of the principal components of locomotion.From the results,we conclude that lateral translation plays a crucial role in propulsion while body undulation in tandem with rotation and head motion reduce the locomotor cost.展开更多
Puppet emperors,red films and meat stews在长春,你不仅能见到伪满洲国和新中国的历史,还能见到蓝天、斜阳和静谧的冬季。You wouldn’t notice that the Changchun Film Studio near the city center is abandoned until you got clo...Puppet emperors,red films and meat stews在长春,你不仅能见到伪满洲国和新中国的历史,还能见到蓝天、斜阳和静谧的冬季。You wouldn’t notice that the Changchun Film Studio near the city center is abandoned until you got close.It’s then that you spot the crumbling stonework,the peeling window frames and the faded revolutionary quotes on the wall.Their originator—a gigantic,beaming Mao Zedong—waves paternally at the gate,where展开更多
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary force correction is used to save the computational cost and memory,and the momentum forcing is described by a simple direct force formula without complicated integral calculation when the velocity correction at the boundary node is determined.With the presented flow solver,the hydrodynamic interaction between the fish-induced dynamic stall vortices and the incoming vortices in unsteady flow is analyzed.Numerical simulation results unveil the mechanism of fish exploiting vortices to enhance their own hydrodynamic performances.The superior swimming performances originate from the relative movement between the“merged vortex”and the locomotion of the fishtail,which is controlled by the phase difference.Formation conditions of the“merged vortex”become the key factor for fish to exploit vortices to improve their swimming performance.We further discuss the effect of the principal components of locomotion.From the results,we conclude that lateral translation plays a crucial role in propulsion while body undulation in tandem with rotation and head motion reduce the locomotor cost.
文摘Puppet emperors,red films and meat stews在长春,你不仅能见到伪满洲国和新中国的历史,还能见到蓝天、斜阳和静谧的冬季。You wouldn’t notice that the Changchun Film Studio near the city center is abandoned until you got close.It’s then that you spot the crumbling stonework,the peeling window frames and the faded revolutionary quotes on the wall.Their originator—a gigantic,beaming Mao Zedong—waves paternally at the gate,where
