We investigate phase diffusion of a two-component Bose--Einstein condensates prepared initially in arbitrary coherent spin state ｜θ0,φ0｜. Analytical expression of the phase-diffusion time is presented for θ0～π/...We investigate phase diffusion of a two-component Bose--Einstein condensates prepared initially in arbitrary coherent spin state ｜θ0,φ0｜. Analytical expression of the phase-diffusion time is presented for θ0～π/2 case. In comparison with the symmetrical case （i.e., θ0=π/2）, we find that the diffusion process becomes slow due to the reduced atom number variance.展开更多
The steady three-dimensional problem of condensation film on an inclined rotating disk is illustrated in this study. The governing non-linear partial differential equations are reduced to the nonlinear ordinary differ...The steady three-dimensional problem of condensation film on an inclined rotating disk is illustrated in this study. The governing non-linear partial differential equations are reduced to the nonlinear ordinary differential equations system by similarity transform. The analytical solution applied to solve this system is the Akbari-Ganji's method (AGM). The velocity and temperature profiles are shown and the influence of Prandtl number and rotation ratio on the flow field, heat transfer and the Nusselt number are discussed in detail. The validity of our solutions is verified by the numerical results.展开更多
In the present study, a computational fluid dynamics method has been applied to investigate the effects of initial degree of supersaturation at reservoir condition on under-expanded sonic jet structures, such as Mach ...In the present study, a computational fluid dynamics method has been applied to investigate the effects of initial degree of supersaturation at reservoir condition on under-expanded sonic jet structures, such as Mach disk location and diameter, barrel shock wave and jet boundary. The axisymmetric nozzle geometry investigated was a converging nozzle with straight part. As a result, it was found that the overpressures due to condensation generate and the characteristics of flow with generation of overpressure due to condensation in the jet were different from those without condensation.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 10804007)the Special Research Foundation and Development Program (Grant No. 200800041003)Research Funds of Beijing Jiaotong University (Grant No. 2007XM049)
文摘We investigate phase diffusion of a two-component Bose--Einstein condensates prepared initially in arbitrary coherent spin state ｜θ0,φ0｜. Analytical expression of the phase-diffusion time is presented for θ0～π/2 case. In comparison with the symmetrical case （i.e., θ0=π/2）, we find that the diffusion process becomes slow due to the reduced atom number variance.
文摘The steady three-dimensional problem of condensation film on an inclined rotating disk is illustrated in this study. The governing non-linear partial differential equations are reduced to the nonlinear ordinary differential equations system by similarity transform. The analytical solution applied to solve this system is the Akbari-Ganji's method (AGM). The velocity and temperature profiles are shown and the influence of Prandtl number and rotation ratio on the flow field, heat transfer and the Nusselt number are discussed in detail. The validity of our solutions is verified by the numerical results.
文摘In the present study, a computational fluid dynamics method has been applied to investigate the effects of initial degree of supersaturation at reservoir condition on under-expanded sonic jet structures, such as Mach disk location and diameter, barrel shock wave and jet boundary. The axisymmetric nozzle geometry investigated was a converging nozzle with straight part. As a result, it was found that the overpressures due to condensation generate and the characteristics of flow with generation of overpressure due to condensation in the jet were different from those without condensation.
