稳定分子流密度非平衡态的速度分布和碰壁率关系

THE VELOCITY DISTRIBUTION FUNCTION AND THE RATE AT WHICH MOLECULES STRIKE A WALL FOR THE DENSITY NON-EQUILIBRIUM STATE IN THE MOLECULAR-FLOW REGION

在分子流状态,空间分子特性决定于表面发射分子的角分布和速率分布。作者发现速率分布可用“立方定律”描述。从表面分子发射规律出发导出了稳定分子流密度非平衡态空间分子速度分布函数。它和麦克斯韦分布不同,是各向异性的。但在立方定律成立时速率却服从麦氏分布。这种状态下碰壁率和分子密度关系是(ε/4)(n(?)),通常可用ε和1的差别表征偏离平衡态的程度。

In the molecular-flow region, the characteristics for the space molecules depend on the angular and speed distribution function for motecutes scattering from the wall. It has been found that the speed distribution function is expressed as the so-called 'Cubic Law', On the basis of the laws obeied by molecules scattering from the wall, the velocity distribution function for the space molecules has been deduced for the density non-equilibrium state in the molecular-flow region. This distribution function is different from Mexwell's and it is an anisotropy. But, the speed distribution function is Mexwell's if 'Cubic Law' is real. For the state mentioned above, the rate per unite area at which molecules strike a wall is (ε/4) n(?), In general, ε is not one and their difference can indicate the extent to which the state deviate from an equilibrium.