Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.A...Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.Around the beginning of this century,China Academy of Engineering Physics(CAEP)began to build some experimental facilities for HEDP investigations,among which the Primary Test Stand(PTS),a multi-module pulsed power facility with a nominal current of 10 MA and a current rising time~90 ns,is an important achievement on the roadmap of the electro-magnetically driven inertial confinement fusion(ICF)researches.PTS is the first pulsed power facility beyond 10 TW in China.Therefore,all the technologies have to be demonstrated,and all the engineering issues have to be overcome.In this article,the research outline,key technologies and the preliminary HEDP experiments are reviewed.Prospects on HEDP research on PTS and pulsed power development for the next step are also discussed.展开更多
The type PT-821 PT Pump test stand and type PT-881 injector test stand are a set of special test stands for calibration of PT Pumps and injectors of Cummins engines. Both test stands may be used in conjunction with an...The type PT-821 PT Pump test stand and type PT-881 injector test stand are a set of special test stands for calibration of PT Pumps and injectors of Cummins engines. Both test stands may be used in conjunction with any model of Bosch injection pump test benches for PT Pumps and injector calibration. During PT Pump calibration, the type PT-821 test stand should be used in conjunction with a Bosch injection pump lest bench. The PT Pump to be tested is installed on the Bosch injection pump test bench through a mounting bracket and is driven by the bench shaft. When calibrating PT injectors, both the PT-881 injector test stand and the PT-821 PT Pump test stand should be used in conjunction with a Bosch injection pump test bench, with the PT-881 injector test stand installed on Bosch test bench. The injector to be tested is driven by the Bosch injection pump test bench through a coupling. This paper describes the structure and function of the PT-821 PT Pump test stand and PT-881 injector test stand. Some technical problems arc described in detail.展开更多
A flexible high power RF test stand has been designed and constructed at IHEP to test a variety of 500 MHz superconducting RF components for the upgrade project of the Beijing Electron Positron Collider （BEPC ）, suc...A flexible high power RF test stand has been designed and constructed at IHEP to test a variety of 500 MHz superconducting RF components for the upgrade project of the Beijing Electron Positron Collider （BEPC ）, such as the input coupler, the higher order modes （HOMs） absorber and so on. A high power input coupler has been conditioned and tested with the RF power up to 250 kW in continuous wave （CW）, traveling wave （TW） mode and 150 kW CW in standing wave （SW） mode. A prototype of the HOMs absorber has been tested to absorb power of 4.4 kW. An introduction of the test stand design, construction and high power tests is presented in this paper.展开更多
After successfully containing the biggest flood this century, the Three Gorges Dam,on the upper reaches of the Yangtze River in central China’s Hubei Province, has encountered another flood, that of public opinion:Wi...After successfully containing the biggest flood this century, the Three Gorges Dam,on the upper reaches of the Yangtze River in central China’s Hubei Province, has encountered another flood, that of public opinion:Will this dam be able to hold floods that are "once-in-10,000-years" or "once-in-1,000-years" or "once-in-a-century"? Should numerous hazards this year, including land and mudslides and mountain torrents,be blamed on accumulation of sediment caused by the construction of the Three Gorges Dam? To get answers to these questions,journalists from Xinhua News Agency interviewed Cao Guangjing, Board Chairman of the China Three Gorges Corp., the operator of the Three Gorges Dam.展开更多
This paper presents an analytical, numerical, and experimental study on atomization characteristics and droplet distribution of a twin-fluid two-phase internal mixing atomizer to develop a Maximum Entropy Method(MEM)....This paper presents an analytical, numerical, and experimental study on atomization characteristics and droplet distribution of a twin-fluid two-phase internal mixing atomizer to develop a Maximum Entropy Method(MEM). A two-phase Eulerian-Lagrangian method is utilized for atomization modeling of the inside and outside atomizer. In order to modify energy and momentum sources in the MEM, parametric studies are performed, and experimental tests are carried out to verify the results by applying the shadowgraph method. An advanced test stand is developed to prepare a wide range of changes in atomization characteristics and mixing ratios. A high degree of consistency is found between numerical results from the developed MEM and experimental tests with different gas-phase pressures and liquid flow rates. The droplet diameter and velocity distribution are reviewed based on various Weber numbers, sources of energy, and momentum. Turbulence modeling assists to estimate the breakup length and time scale precisely in the developed MEM, and distribution ranges with mean values are achieved. With reference to a strong correlation between upstream turbulence flow and the developed MEM verified by experimental tests, an ideal droplet size and velocity distribution prediction is observed.展开更多
文摘Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.Around the beginning of this century,China Academy of Engineering Physics(CAEP)began to build some experimental facilities for HEDP investigations,among which the Primary Test Stand(PTS),a multi-module pulsed power facility with a nominal current of 10 MA and a current rising time~90 ns,is an important achievement on the roadmap of the electro-magnetically driven inertial confinement fusion(ICF)researches.PTS is the first pulsed power facility beyond 10 TW in China.Therefore,all the technologies have to be demonstrated,and all the engineering issues have to be overcome.In this article,the research outline,key technologies and the preliminary HEDP experiments are reviewed.Prospects on HEDP research on PTS and pulsed power development for the next step are also discussed.
文摘The type PT-821 PT Pump test stand and type PT-881 injector test stand are a set of special test stands for calibration of PT Pumps and injectors of Cummins engines. Both test stands may be used in conjunction with any model of Bosch injection pump test benches for PT Pumps and injector calibration. During PT Pump calibration, the type PT-821 test stand should be used in conjunction with a Bosch injection pump lest bench. The PT Pump to be tested is installed on the Bosch injection pump test bench through a mounting bracket and is driven by the bench shaft. When calibrating PT injectors, both the PT-881 injector test stand and the PT-821 PT Pump test stand should be used in conjunction with a Bosch injection pump test bench, with the PT-881 injector test stand installed on Bosch test bench. The injector to be tested is driven by the Bosch injection pump test bench through a coupling. This paper describes the structure and function of the PT-821 PT Pump test stand and PT-881 injector test stand. Some technical problems arc described in detail.
基金Supported by Key Scientific Equipment Projects of Chinese Academy of Sciences(YZ200809)
文摘A flexible high power RF test stand has been designed and constructed at IHEP to test a variety of 500 MHz superconducting RF components for the upgrade project of the Beijing Electron Positron Collider （BEPC ）, such as the input coupler, the higher order modes （HOMs） absorber and so on. A high power input coupler has been conditioned and tested with the RF power up to 250 kW in continuous wave （CW）, traveling wave （TW） mode and 150 kW CW in standing wave （SW） mode. A prototype of the HOMs absorber has been tested to absorb power of 4.4 kW. An introduction of the test stand design, construction and high power tests is presented in this paper.
文摘After successfully containing the biggest flood this century, the Three Gorges Dam,on the upper reaches of the Yangtze River in central China’s Hubei Province, has encountered another flood, that of public opinion:Will this dam be able to hold floods that are "once-in-10,000-years" or "once-in-1,000-years" or "once-in-a-century"? Should numerous hazards this year, including land and mudslides and mountain torrents,be blamed on accumulation of sediment caused by the construction of the Three Gorges Dam? To get answers to these questions,journalists from Xinhua News Agency interviewed Cao Guangjing, Board Chairman of the China Three Gorges Corp., the operator of the Three Gorges Dam.
文摘This paper presents an analytical, numerical, and experimental study on atomization characteristics and droplet distribution of a twin-fluid two-phase internal mixing atomizer to develop a Maximum Entropy Method(MEM). A two-phase Eulerian-Lagrangian method is utilized for atomization modeling of the inside and outside atomizer. In order to modify energy and momentum sources in the MEM, parametric studies are performed, and experimental tests are carried out to verify the results by applying the shadowgraph method. An advanced test stand is developed to prepare a wide range of changes in atomization characteristics and mixing ratios. A high degree of consistency is found between numerical results from the developed MEM and experimental tests with different gas-phase pressures and liquid flow rates. The droplet diameter and velocity distribution are reviewed based on various Weber numbers, sources of energy, and momentum. Turbulence modeling assists to estimate the breakup length and time scale precisely in the developed MEM, and distribution ranges with mean values are achieved. With reference to a strong correlation between upstream turbulence flow and the developed MEM verified by experimental tests, an ideal droplet size and velocity distribution prediction is observed.
