The residence time distribution （RTD） of solids and the fluidized structure of a bubbling fluidized bed were investigated numerically using computational fluid dynamics simulations coupled with the modified structur...The residence time distribution （RTD） of solids and the fluidized structure of a bubbling fluidized bed were investigated numerically using computational fluid dynamics simulations coupled with the modified structure-based drag model. A general comparison of the simulated results with theoretical values shows reasonable agreement. As the mean residence time is increased, the RTD initial peak intensity decreases and the RTD curve tail extends farther. Numerous small peaks on the RTD curve are induced by the back- mixing and aggregation of particles, which attests to the non-uniform flow structure of the bubbling fluidized bed. The low value of t50 results in poor contact between phases, and the complete exit age of the overflow particles is much longer for back-mixed solids and those caught in dead regions. The formation of a gulf-stream flow and back-mixing for solids induces an even wider spread of RTD.展开更多
This paper proposes a new Graphics Processing Unit(GPU)-accelerated storage format to speed up Sparse Matrix Vector Products(SMVPs) for Finite Element Method(FEM) analysis of electromagnetic problems.A new format call...This paper proposes a new Graphics Processing Unit(GPU)-accelerated storage format to speed up Sparse Matrix Vector Products(SMVPs) for Finite Element Method(FEM) analysis of electromagnetic problems.A new format called Modified Compile Time Optimization(MCTO) format is used to reduce much execution time and design for hastening the iterative solution of FEM equations especially when rows have uneven lengths.The MCTO-applied FEM is about 10 times faster than conventional FEM on a CPU,and faster than other row-major ordering formats on a GPU.Numerical results show that the proposed GPU-accelerated storage format turns out to be an excellent accelerator.展开更多
文摘The residence time distribution （RTD） of solids and the fluidized structure of a bubbling fluidized bed were investigated numerically using computational fluid dynamics simulations coupled with the modified structure-based drag model. A general comparison of the simulated results with theoretical values shows reasonable agreement. As the mean residence time is increased, the RTD initial peak intensity decreases and the RTD curve tail extends farther. Numerous small peaks on the RTD curve are induced by the back- mixing and aggregation of particles, which attests to the non-uniform flow structure of the bubbling fluidized bed. The low value of t50 results in poor contact between phases, and the complete exit age of the overflow particles is much longer for back-mixed solids and those caught in dead regions. The formation of a gulf-stream flow and back-mixing for solids induces an even wider spread of RTD.
基金Supported by the National Science Foundation of China(Nos.61272097,71203064,71103077)the Natural Science Foundation of Shanghai(No.12ZR1443000)+2 种基金the Funding Research and Innovation Project of Shanghai Municipal Education Commission(No.12ZZ182)the Fundamental Research Funds for the Central Universitiesand the Local Colleges and Universities "1025" Connotation Construction Project of Shanghai(No.nhky-2012-10)the Foundation of Shanghai University of Engineering Science(No.A-0501-13-012)
文摘This paper proposes a new Graphics Processing Unit(GPU)-accelerated storage format to speed up Sparse Matrix Vector Products(SMVPs) for Finite Element Method(FEM) analysis of electromagnetic problems.A new format called Modified Compile Time Optimization(MCTO) format is used to reduce much execution time and design for hastening the iterative solution of FEM equations especially when rows have uneven lengths.The MCTO-applied FEM is about 10 times faster than conventional FEM on a CPU,and faster than other row-major ordering formats on a GPU.Numerical results show that the proposed GPU-accelerated storage format turns out to be an excellent accelerator.
