Temperature of a granular material "fluidized" by external vibrations
Temperature of a granular material "fluidized" by external vibrations
复制标题
外部振动“流化”的颗粒材料的温度
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
V. Kumaran
中科院分区：
文献类型：
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作者：
V. Kumaran
通过外部振动“流化”的粒状材料的温度缩放是在以下限度内确定的：由于非弹性而导致的碰撞中或由于粘性阻力而导致的连续碰撞之间的能量耗散与颗粒的能量相比较小。使用渐进方案，其中在领先近似中忽略能量耗散，并且系统的玻尔兹曼方程与引力场中处于平衡状态的气体的玻尔兹曼方程相同。 “流化”材料中的密度变化由玻尔兹曼分布给出，速度分布由麦克斯韦-玻尔兹曼分布给出。然而，材料的“温度”并不是由热力学考虑指定的，而是由振动表面产生的能量来源与能量耗散之间的平衡决定。这种平衡表明，温度对振动表面振幅的依赖性敏感地取决于耗散机制（非弹性碰撞或粘性阻力），并且还取决于振动表面速度的振幅函数关于零速度是对称还是不对称。然而，事实证明，温度对二维和三维系统的特性具有相同的函数依赖性。
The scaling for the temperature of a granular material "fluidized" by external vibrations is determined in the limit where the dissipation of energy in a collision due to inelasticity, or between successive collisions due to viscous drag, is small compared to the energy of the particles. An asymptotic scheme is used, where the dissipation of energy is neglected in the leading approximation, and the Boltzmann equation for the system is identical to that for a gas at equilibrium in a gravitational field. The density variation in the "fluidized" material is given by the Boltzmann distribution, and the velocity distribution is given by the Maxwell-Boltzmann distribution. However, the "temperature" of the material is not specified by thermodynamic considerations, but is determined by a balance between the source of energy due to the vibrating surface and the dissipation of energy. This balance indicates that the dependence of temperature on the amplitude of the vibrating surface is sensitively dependent on the mechanism of dissipation (inelastic collisions or viscous drag), and also on whether the amplitude function for the velocity of the vibrating surface is symmetric or asymmetric about zero velocity. However, the temperature turns out to have the same functional dependence on the properties of the system in two and three dimensions.