摘要
利用在微重力环境下获得的稀薄颗粒体系长时间(2h)运动的录像数据,得到了颗粒气体的非高斯速度几率分布,分布函数接近负e指数.应用湍流中的朗之万方程修正形式,探讨给出颗粒体系速度几率分布函数普适表达式的可能性.
Velocity distribution of a quasi-2D dissipative granular gas in the limit of Knudsen regime is obtained experimentally in microgravity condition. The distribution is found to follow an exponential function, which deviates strongly from the Boltzmann distribution as in the molecular gas. A close form expression of the probability density function P（v） of the velocity distribution, derived from a modified Langevin equation, is found to fit the experimental data. Depending on the value of the fitting parameter a in the function q（v）=Q（v2＋a2）1/2, the function P（v） can be a function from Gaussian when a is large compared with v, to exponential distribution when a is much smaller than v. This close form function may give a generic expression to the granular gas velocity distribution in different experimental conditions.
出处
《科学通报》
EI
CAS
CSCD
北大核心
2009年第11期1483-1487,共5页
Chinese Science Bulletin
基金
国家自然科学基金(批准号:10720101074
10874209)
中国科学院知识创新工程重要方向性项目(编号:KKCX1-YW-03
KJCX2-YW-L08)资助
关键词
颗粒物质
速度分布律
朗之万方程
granular matter, velocity distribution, Langevin equation
