The computational fluid dynamics （CFD） method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisa...The computational fluid dynamics （CFD） method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisation. The detached-eddy simulation （DES） based on the Spalart-Allmaras one-equation turbulence model is ap- plied to the detached viscous flow simulation behind the seat/occupant, with Mach numbers 0.6 and 1.2 at attack angles between --10 and 30°, and at two sideslip angles of 0 and 15°, respectively. The aerodynamic characteristics of seat/occupants with and without windblast protection devices are calculated in cases of the freestream Mach numbers 0. 8 and 1.6, attack angles from 5 to 30°, and three sideslip angles of 0, --20 and --50°, respectively. Results show that simulation results agree well with experimental data. And the occupant is efficiently protected by windblast protection devices.展开更多
DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the pa...DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the parallel inverter system without output isolation transformers, the difference of DC components of the output voltage can cause large DC loop-current among modular inverters. Aiming at this problem, this paper studies several DC loop-current detecting and restraining methods. By digital adjustment with high precision on the DC components of reference sine wave, the DC components of inverter′s output voltage can be adjusted to restrain DC loop-current. Experimental results prove that the DC loop-current detecting and restraining methods have a good performance.展开更多
From an economical point of view, both foe quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful Performance.In general, two different tec...From an economical point of view, both foe quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful Performance.In general, two different technologies have been established on the market. The main differences between the CO-- and counter current technologies will be discussed and data concerning the requirement of chemicale for regeneration and the quality of the deionized water will be opposed.In addition several different varieties of the modern counter current technologies, developed and patented by Bayer AG, will be described and the advantages,depending on the application and the demand on the quality of the deionized water,pointed out. In view of stronger regulations concerning the consumption of regeneration chemicals, and waste water, and also because of the superior quality of the produced water, the market share of counter current technologies will continue to increase world--wide.展开更多
基金Supported by the Aeronautical Science Foundation of China(2008ZC52039)~~
文摘The computational fluid dynamics （CFD） method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisation. The detached-eddy simulation （DES） based on the Spalart-Allmaras one-equation turbulence model is ap- plied to the detached viscous flow simulation behind the seat/occupant, with Mach numbers 0.6 and 1.2 at attack angles between --10 and 30°, and at two sideslip angles of 0 and 15°, respectively. The aerodynamic characteristics of seat/occupants with and without windblast protection devices are calculated in cases of the freestream Mach numbers 0. 8 and 1.6, attack angles from 5 to 30°, and three sideslip angles of 0, --20 and --50°, respectively. Results show that simulation results agree well with experimental data. And the occupant is efficiently protected by windblast protection devices.
文摘DC component is contained in inverter output voltage due to many reasons such as the zero-point deviation of operational amplifiers and the differences between power switching transistors′ characteristics. For the parallel inverter system without output isolation transformers, the difference of DC components of the output voltage can cause large DC loop-current among modular inverters. Aiming at this problem, this paper studies several DC loop-current detecting and restraining methods. By digital adjustment with high precision on the DC components of reference sine wave, the DC components of inverter′s output voltage can be adjusted to restrain DC loop-current. Experimental results prove that the DC loop-current detecting and restraining methods have a good performance.
文摘From an economical point of view, both foe quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful Performance.In general, two different technologies have been established on the market. The main differences between the CO-- and counter current technologies will be discussed and data concerning the requirement of chemicale for regeneration and the quality of the deionized water will be opposed.In addition several different varieties of the modern counter current technologies, developed and patented by Bayer AG, will be described and the advantages,depending on the application and the demand on the quality of the deionized water,pointed out. In view of stronger regulations concerning the consumption of regeneration chemicals, and waste water, and also because of the superior quality of the produced water, the market share of counter current technologies will continue to increase world--wide.
