The Zeldovich-Frank-Kamenetskii solution for the flame velocity of a planar front with one-step overall chemical reaction was enhanced. The assumption that the consumption rate depends exclusively on a chemical compon...The Zeldovich-Frank-Kamenetskii solution for the flame velocity of a planar front with one-step overall chemical reaction was enhanced. The assumption that the consumption rate depends exclusively on a chemical component was removed. Instead, the reaction rate was considered to be dependent on all reactants of an overall reaction. The new formulation was applied to obtain the activation energy and the pre-exponential factor of a set of hydrogen-air mixtures.展开更多
By studying of a slender body moving in a fluid wave-medium, e.g., in air or in shallow water, it was found that the hydrodynamic momentum mass and the total energy of the fluid field can be expressed in forms of and ...By studying of a slender body moving in a fluid wave-medium, e.g., in air or in shallow water, it was found that the hydrodynamic momentum mass and the total energy of the fluid field can be expressed in forms of and E=mc<sup>2</sup>, where v is the body moving speed, c is the wave speed and is the hydrodynamic mass at the zero speed. Thus a hydrodynamic analogy to the relativistic particle motion in vacuum can be traced. The velocity dependence of mass and the mass-energy equivalence are universal for any wave medium, which should not be regarded as a consequence of relative Lorentz time-space, but one of the existence of wave in the medium. Its further inference leads to an even more significant physical picture. If the mass particle moves in an unbounded space at a supercritical speed, i.e. , waves are generated and radiated from it, like the Mach waves by the supersonic plane, and the particle itself experiences a resistance as reaction from the wave radiation. By an extension of this analogy, it can be interred from a hydrodynamic superconductive phenomenon that particles or waves can move possibly at a superluminal speed without experiencing any resistance through a tunnel (a bounded space) under certain conditions. Therefore the speed of light is not the limit of our physical world and superluminal phenomena are possible.展开更多
The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on th...The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on this concept,a stepwise radial fuel shuffling strategy was proposed and applied to a sodium-cooled fast reactor(SFR)loading metallic 238U fuel.The multi-group deterministic neutronic code ERANOS with JEFF3.1 data library was used as a basic tool to perform the neutronics and burnup calculations.The inward fuel shuffling calculations were first performed in a 1-D cylindrical case for parametric understanding,and then extended to a 2-D R-Z case.The shuffling calculations for the 1-D and 2-D SFR model yielded some interesting results.The asymptotic keff varied parabolically with the characteristic fluence,while the burnup increased linearly.The highest burnup achieved in 2-D case was 38%.The power peak shifted from the fuel outlet side(core centre)to the fuel inlet side(core periphery)in both 1-D and 2-D cases and the corresponding peaking factor decreased dramatically along with the characteristic fluence.The present research demonstrated that the proposed stepwise radial fuel shuffling in the sodium fast reactor achieved the characteristics of the traveling wave reactor.展开更多
文摘The Zeldovich-Frank-Kamenetskii solution for the flame velocity of a planar front with one-step overall chemical reaction was enhanced. The assumption that the consumption rate depends exclusively on a chemical component was removed. Instead, the reaction rate was considered to be dependent on all reactants of an overall reaction. The new formulation was applied to obtain the activation energy and the pre-exponential factor of a set of hydrogen-air mixtures.
文摘By studying of a slender body moving in a fluid wave-medium, e.g., in air or in shallow water, it was found that the hydrodynamic momentum mass and the total energy of the fluid field can be expressed in forms of and E=mc<sup>2</sup>, where v is the body moving speed, c is the wave speed and is the hydrodynamic mass at the zero speed. Thus a hydrodynamic analogy to the relativistic particle motion in vacuum can be traced. The velocity dependence of mass and the mass-energy equivalence are universal for any wave medium, which should not be regarded as a consequence of relative Lorentz time-space, but one of the existence of wave in the medium. Its further inference leads to an even more significant physical picture. If the mass particle moves in an unbounded space at a supercritical speed, i.e. , waves are generated and radiated from it, like the Mach waves by the supersonic plane, and the particle itself experiences a resistance as reaction from the wave radiation. By an extension of this analogy, it can be interred from a hydrodynamic superconductive phenomenon that particles or waves can move possibly at a superluminal speed without experiencing any resistance through a tunnel (a bounded space) under certain conditions. Therefore the speed of light is not the limit of our physical world and superluminal phenomena are possible.
基金supported by the National Natural Science Foundation of China(Grant No.11105103)the Doctoral Fund of the Ministry of Education of China(Grant No.20110201120046)
文摘The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on this concept,a stepwise radial fuel shuffling strategy was proposed and applied to a sodium-cooled fast reactor(SFR)loading metallic 238U fuel.The multi-group deterministic neutronic code ERANOS with JEFF3.1 data library was used as a basic tool to perform the neutronics and burnup calculations.The inward fuel shuffling calculations were first performed in a 1-D cylindrical case for parametric understanding,and then extended to a 2-D R-Z case.The shuffling calculations for the 1-D and 2-D SFR model yielded some interesting results.The asymptotic keff varied parabolically with the characteristic fluence,while the burnup increased linearly.The highest burnup achieved in 2-D case was 38%.The power peak shifted from the fuel outlet side(core centre)to the fuel inlet side(core periphery)in both 1-D and 2-D cases and the corresponding peaking factor decreased dramatically along with the characteristic fluence.The present research demonstrated that the proposed stepwise radial fuel shuffling in the sodium fast reactor achieved the characteristics of the traveling wave reactor.
