The LBGK(lattice Bhatnagar-Gross-Krook)model of the lattice Boltzmann method including second-order boundary condition treatment for curve geometry was employed to investigate the flow around particle clusters.The dra...The LBGK(lattice Bhatnagar-Gross-Krook)model of the lattice Boltzmann method including second-order boundary condition treatment for curve geometry was employed to investigate the flow around particle clusters.The drag coefficient is a benchmark problem in the analysis of particle-fluid complex systems,especially,in a gas-solid fluidized bed.In the present work,the drag coefficient on a spherical particle in a cluster,was evaluated by using the momentum-exchange method directly.Two different configurations of cluster were measured based on the lattice Boltzmann method.Computational results indicated that the drag coefficient on an individual particle in a cluster depended heavily on the configuration of cluster.And the drag coefficient on the particle in the cluster was lower when that particle was shielded by other particles.Additionally,except for the configuration factor,both the inter-distance and Reynolds number had a strong effect on the drag coefficient on an individual particle as well.It was found that the drag coefficient on each particle varied drastically with clustering.Omitting the effect of clustering might result in incorrect drag forces in the simulation.展开更多
Interrupt-driven systems can be collapsed due to frequent NIC interrupts under heavy network traffic. To mitigate this problem, a high-performance communication mechanism SBIM based on real-time OS RTLinux is designed...Interrupt-driven systems can be collapsed due to frequent NIC interrupts under heavy network traffic. To mitigate this problem, a high-performance communication mechanism SBIM based on real-time OS RTLinux is designed and implemented. A new concept of semi-polling is presented. With state-based semi-polling mechanism and lightweight buffeting algorithm, interrupt frequency is reduced and the performance for short packet is significantly ameliorated. The experimental results indicate that the throughputs of SBIM for 64byte and 1500byte packets are 394Mbps and 895Mbps in Gigabit Ethernet environments, which show that the performance of SBIM surpasses that of other mechanisms展开更多
文摘The LBGK(lattice Bhatnagar-Gross-Krook)model of the lattice Boltzmann method including second-order boundary condition treatment for curve geometry was employed to investigate the flow around particle clusters.The drag coefficient is a benchmark problem in the analysis of particle-fluid complex systems,especially,in a gas-solid fluidized bed.In the present work,the drag coefficient on a spherical particle in a cluster,was evaluated by using the momentum-exchange method directly.Two different configurations of cluster were measured based on the lattice Boltzmann method.Computational results indicated that the drag coefficient on an individual particle in a cluster depended heavily on the configuration of cluster.And the drag coefficient on the particle in the cluster was lower when that particle was shielded by other particles.Additionally,except for the configuration factor,both the inter-distance and Reynolds number had a strong effect on the drag coefficient on an individual particle as well.It was found that the drag coefficient on each particle varied drastically with clustering.Omitting the effect of clustering might result in incorrect drag forces in the simulation.
文摘Interrupt-driven systems can be collapsed due to frequent NIC interrupts under heavy network traffic. To mitigate this problem, a high-performance communication mechanism SBIM based on real-time OS RTLinux is designed and implemented. A new concept of semi-polling is presented. With state-based semi-polling mechanism and lightweight buffeting algorithm, interrupt frequency is reduced and the performance for short packet is significantly ameliorated. The experimental results indicate that the throughputs of SBIM for 64byte and 1500byte packets are 394Mbps and 895Mbps in Gigabit Ethernet environments, which show that the performance of SBIM surpasses that of other mechanisms
