Three-dimensional flow field of turbine in torque converter is simulated by numerical calculation in order to improve the performance of torque converter. Calculation model of a torque converter is presented based on ...Three-dimensional flow field of turbine in torque converter is simulated by numerical calculation in order to improve the performance of torque converter. Calculation model of a torque converter is presented based on the mixing-plane technology. In the calculation of flow field, the 3D N-S equations are separated by finite-volume method and solved by semi-implicit method for pressure-linked equations（SIMPLE）. Based on flow field calculation, the flow field of turbine is simulated. The velocity and pressure in the flow field of turbine are analyzed. The external performance of the torque converter is also calculated. Results of flow simulation show that there are secondary flow, off flow and velocity gradient in turbine passage. The validity of numerical simulation is verified by comparing the results of numerical simulation with experiment data.展开更多
The United States was the first country in the world to develop a satellite navigation system,with rich experience in system management,R&D,operation,and satellite applications industry.It started the construction...The United States was the first country in the world to develop a satellite navigation system,with rich experience in system management,R&D,operation,and satellite applications industry.It started the construction of the Global Positioning System(GPS)in 1973 and deployed the first satellite in 1978.It has successfully developed and deployed three series of GPS satellites with a total of seven models.The United States is now focusing on the research and development of cutting edge navigation technologies and constellation modernization,replacing old ones with new GPS III series of satellites and actively exploring and verifying the frontier navigation technologies represented through the Navigation Technology Satellite 3(NTS-3).It is now upgrading the original ground-based operation and control system,actively developing and deploying the GPS Next Generation Operational Control System(GPS OCX),and upgrading the military user equipment supporting Military Code(M-Code).The U.S.attaches importance to multiple measures to improve the service performance of the GPS system and enhance the resilience of the system to provide positioning,navigation,and timing capabilities.In this context,the progress of the construction of GPS and the related technological innovations are separated out and analyzed,which will help the Global Navigation Satellite System(GNSS)solutions summarizing their experience and learning from each other’s development to better serve social progress and economic development.展开更多
<正>Crystalline SiO2(c-SiO2) samples were firstly implanted at room temperature (RT) with 120 keV Cions and then irradiated at RT with 950 MeV Pb ions. The C-ion irradiation experiments were performed on the 200...<正>Crystalline SiO2(c-SiO2) samples were firstly implanted at room temperature (RT) with 120 keV Cions and then irradiated at RT with 950 MeV Pb ions. The C-ion irradiation experiments were performed on the 200 kV heavy ion implanter of IMP and the selected implantation doses are 2. 0×1017 , 5. 0×1017, 8. 6×1017 and 1. 2×1017C/cm2. The Pb ion irradiation was carried out at the IRASME (CIRIL-GANIL, Caen) and the irradiation fluencies are 5.0×1011,1. 0×1012 and 1..0×1012 Pb/cm2 , respectively. The chemical bonds formation in the samples was investigated by using a Spectrum GX IR spectroscopy.展开更多
基金This project is supported by National Natural Science Foundation of China (No. 50175042).
文摘Three-dimensional flow field of turbine in torque converter is simulated by numerical calculation in order to improve the performance of torque converter. Calculation model of a torque converter is presented based on the mixing-plane technology. In the calculation of flow field, the 3D N-S equations are separated by finite-volume method and solved by semi-implicit method for pressure-linked equations（SIMPLE）. Based on flow field calculation, the flow field of turbine is simulated. The velocity and pressure in the flow field of turbine are analyzed. The external performance of the torque converter is also calculated. Results of flow simulation show that there are secondary flow, off flow and velocity gradient in turbine passage. The validity of numerical simulation is verified by comparing the results of numerical simulation with experiment data.
文摘The United States was the first country in the world to develop a satellite navigation system,with rich experience in system management,R&D,operation,and satellite applications industry.It started the construction of the Global Positioning System(GPS)in 1973 and deployed the first satellite in 1978.It has successfully developed and deployed three series of GPS satellites with a total of seven models.The United States is now focusing on the research and development of cutting edge navigation technologies and constellation modernization,replacing old ones with new GPS III series of satellites and actively exploring and verifying the frontier navigation technologies represented through the Navigation Technology Satellite 3(NTS-3).It is now upgrading the original ground-based operation and control system,actively developing and deploying the GPS Next Generation Operational Control System(GPS OCX),and upgrading the military user equipment supporting Military Code(M-Code).The U.S.attaches importance to multiple measures to improve the service performance of the GPS system and enhance the resilience of the system to provide positioning,navigation,and timing capabilities.In this context,the progress of the construction of GPS and the related technological innovations are separated out and analyzed,which will help the Global Navigation Satellite System(GNSS)solutions summarizing their experience and learning from each other’s development to better serve social progress and economic development.
基金Supported by National Natural Science Foundation of China （10125522,10475102）.
文摘<正>Crystalline SiO2(c-SiO2) samples were firstly implanted at room temperature (RT) with 120 keV Cions and then irradiated at RT with 950 MeV Pb ions. The C-ion irradiation experiments were performed on the 200 kV heavy ion implanter of IMP and the selected implantation doses are 2. 0×1017 , 5. 0×1017, 8. 6×1017 and 1. 2×1017C/cm2. The Pb ion irradiation was carried out at the IRASME (CIRIL-GANIL, Caen) and the irradiation fluencies are 5.0×1011,1. 0×1012 and 1..0×1012 Pb/cm2 , respectively. The chemical bonds formation in the samples was investigated by using a Spectrum GX IR spectroscopy.
