Particle-in-cell (PIC) method has got much benefits from GPU-accelerated heterogeneous systems.However,the performance of PIC is constrained by the interpolation operations in the weighting process on GPU (graphic pro...Particle-in-cell (PIC) method has got much benefits from GPU-accelerated heterogeneous systems.However,the performance of PIC is constrained by the interpolation operations in the weighting process on GPU (graphic processing unit).Aiming at this problem,a fast weighting method for PIC simulation on GPU-accelerated systems was proposed to avoid the atomic memory operations during the weighting process.The method was implemented by taking advantage of GPU's thread synchronization mechanism and dividing the problem space properly.Moreover,software managed shared memory on the GPU was employed to buffer the intermediate data.The experimental results show that the method achieves speedups up to 3.5 times compared to previous works,and runs 20.08 times faster on one NVIDIA Tesla M2090 GPU compared to a single core of Intel Xeon X5670 CPU.展开更多
To investigate the differences and the development trends of the 400 kA aluminum reduction cell, four representative cells were deeply analyzed. By using numerical simulation methods in ANSYS software, the structure p...To investigate the differences and the development trends of the 400 kA aluminum reduction cell, four representative cells were deeply analyzed. By using numerical simulation methods in ANSYS software, the structure parameters were firstly compared, and then three-dimensional models of electric-magnetic-flow field were built and solved with finite element method(FEM). The comparison of the structures reveals that the cell bodies are similar while the current flow path and distribution ratio of bus bars are different. It appears that most of the current(70%-80%) in side A are used as the magnetic field compensation current and flow through two ends. The numerical simulation results indicate that the distributions of magnetic fields are different but all satisfy with the magnetohydrodynamics(MHD) stabilization, and the flow patterns are all two or multi vortexes with appropriate velocities. The comparison shows that all studied cells can satisfy with the physical field requirement, and the commercial applications also verify that the 400 kA cells have become the product of the mature and world's leading technology.展开更多
Enhancing the output capacity of semiconductor bridge(SCB)through the application of composite nano-energetic films is a subject of wide concern.Furthermore,improving the safety,reliability,and production efficiency o...Enhancing the output capacity of semiconductor bridge(SCB)through the application of composite nano-energetic films is a subject of wide concern.Furthermore,improving the safety,reliability,and production efficiency of energetic semiconductor bridge(ESCB)is the primary focus for large-scale engineering applications in the future.Here,the Al/CuO nano-film ESCB was efficiently fabricated using 3D direct writing.The electrostatic safety of the film is enhanced by precisely adjusting the particle size of Al,while ensuring that the SCB can initiate the film with small energy.The burst characteristics of SCB/ESCB were thoroughly investigated by employing a 100 mF tantalum capacitor to induce SCB and ESCB under an intense voltage gradient.The solid-state heating process of both SCB and ESCB was analyzed with multi physical simulation(MPS).The experimental results demonstrate that the critical burst time of both SCB and ESCB decreases with increasing voltage.Under the same voltage,the critical burst time of ESCB is longer than that of SCB,primarily due to differences in the melting to vaporization stage.The MPS results indicate that the highest temperature is observed at the V-shaped corner of SCB.Due to the thermal contact resistance between SCB and the film,heat conduction becomes more concentrated in the central region of the bridge,resulting in a faster solid-state heating process for ESCB compared to SCB.The results of the gap ignition experiments indicate that at a 19 mm gap,an ESCB with a film mass of 10 mg can ignite nickel hydrazine nitrate(NHN)and cyclotrimethylenetrinitramine(RDX).This suggests that thermite ESCB can serve as a novel,safe,and reliable energy exchange element and initiator in largescale engineering applications.展开更多
基金Projects(61170049,60903044)supported by National Natural Science Foundation of ChinaProject(2012AA010903)supported by National High Technology Research and Development Program of China
文摘Particle-in-cell (PIC) method has got much benefits from GPU-accelerated heterogeneous systems.However,the performance of PIC is constrained by the interpolation operations in the weighting process on GPU (graphic processing unit).Aiming at this problem,a fast weighting method for PIC simulation on GPU-accelerated systems was proposed to avoid the atomic memory operations during the weighting process.The method was implemented by taking advantage of GPU's thread synchronization mechanism and dividing the problem space properly.Moreover,software managed shared memory on the GPU was employed to buffer the intermediate data.The experimental results show that the method achieves speedups up to 3.5 times compared to previous works,and runs 20.08 times faster on one NVIDIA Tesla M2090 GPU compared to a single core of Intel Xeon X5670 CPU.
基金Projects(51104187,51274241,61321003) supported by the National Natural Science Foundation of ChinaProject(20100162120008) supported by Doctoral Fund of Ministry of Education of China
文摘To investigate the differences and the development trends of the 400 kA aluminum reduction cell, four representative cells were deeply analyzed. By using numerical simulation methods in ANSYS software, the structure parameters were firstly compared, and then three-dimensional models of electric-magnetic-flow field were built and solved with finite element method(FEM). The comparison of the structures reveals that the cell bodies are similar while the current flow path and distribution ratio of bus bars are different. It appears that most of the current(70%-80%) in side A are used as the magnetic field compensation current and flow through two ends. The numerical simulation results indicate that the distributions of magnetic fields are different but all satisfy with the magnetohydrodynamics(MHD) stabilization, and the flow patterns are all two or multi vortexes with appropriate velocities. The comparison shows that all studied cells can satisfy with the physical field requirement, and the commercial applications also verify that the 400 kA cells have become the product of the mature and world's leading technology.
基金supported by the National Natural Science Foundation of China(Grant Nos.22275092 and 52372084)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX24_0709)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.30923010920)the State Key Laboratory of Transient Chemical Effects and Control,China,(Grant No.6142602230201).
文摘Enhancing the output capacity of semiconductor bridge(SCB)through the application of composite nano-energetic films is a subject of wide concern.Furthermore,improving the safety,reliability,and production efficiency of energetic semiconductor bridge(ESCB)is the primary focus for large-scale engineering applications in the future.Here,the Al/CuO nano-film ESCB was efficiently fabricated using 3D direct writing.The electrostatic safety of the film is enhanced by precisely adjusting the particle size of Al,while ensuring that the SCB can initiate the film with small energy.The burst characteristics of SCB/ESCB were thoroughly investigated by employing a 100 mF tantalum capacitor to induce SCB and ESCB under an intense voltage gradient.The solid-state heating process of both SCB and ESCB was analyzed with multi physical simulation(MPS).The experimental results demonstrate that the critical burst time of both SCB and ESCB decreases with increasing voltage.Under the same voltage,the critical burst time of ESCB is longer than that of SCB,primarily due to differences in the melting to vaporization stage.The MPS results indicate that the highest temperature is observed at the V-shaped corner of SCB.Due to the thermal contact resistance between SCB and the film,heat conduction becomes more concentrated in the central region of the bridge,resulting in a faster solid-state heating process for ESCB compared to SCB.The results of the gap ignition experiments indicate that at a 19 mm gap,an ESCB with a film mass of 10 mg can ignite nickel hydrazine nitrate(NHN)and cyclotrimethylenetrinitramine(RDX).This suggests that thermite ESCB can serve as a novel,safe,and reliable energy exchange element and initiator in largescale engineering applications.
