The Effect of the Accommodation Coefficient on Slider Air Bearing Simulation
The Effect of the Accommodation Coefficient on Slider Air Bearing Simulation
复制标题
调节系数对滑块空气轴承仿真的影响
DOI：
10.1115/1.555384
复制
发表时间：
2000
影响因子：
2.5
通讯作者：
D. Bogy
中科院分区：
文献类型：
--
作者：
Weidong Huang;D. Bogy
在解决滑块空气轴承问题时，分子气膜润滑（MGL）模型和直接模拟蒙特卡罗（DSMC）模型都需要调节系数作为输入。调节系数表示以扩散方式与固体边界相互作用的空气分子的分数。通常，值1用于调节系数，其表示完全漫反射。然而，在磁性硬盘驱动器中，磁盘和滑块表面由于磁盘上的不同种类的润滑而变得越来越光滑，而温度由于更快的主轴速度而变得更高。在这些条件下，调节系数的单位值可能不再合适。为了了解调节系数对滑块飞行参数的影响，我们使用Kang的新数据库的Poiffille流率和Couette流率来求解两组滑块的修正雷诺方程，例如，负压和正压滑块（“负压”是指具有低于环境压力区域的滑块）。结果表明，一般情况下，调节系数越小，飞行高度和俯仰角越小。正压滑块比负压滑块对调节系数更敏感。飞行高度的典型差异约为10%。此外，它表明，正压滑块的飞行高度越低，较大的差异百分比。[S0742-4787（00）00402-1]
In solving the slider air bearing problem, both the Molecular Gas-film Lubrication (MGL) model and the Direct Simulation Monte Carlo (DSMC) model require the accommodation coefficient as input. The accommodation coefficient represents the fraction of the air molecules that interact with solid boundaries in a diffusive manner. In general, the value 1 is used for the accommodation coefficient, which represents a fully diffusive reflection. However, in magnetic hard disk drives, the disk and slider surfaces are becoming ever smoother with different kinds of lubrication on the disk, while the temperature is becoming higher due to the faster spindle speed. Under these conditions the unit value of the accommodation coefficient may no longer be suitable. In order to understand the effect of the accommodation coefficient on the slider’s flying parameters, we used Kang’s new database for the Poiseuille flow rateand Couette flow rateto solve the modified Reynolds equation for two groups of sliders, e.g., negative and positive pressure sliders (“negative” refers to sliders with subambient pressure zones). The results show that, in general, the smaller the accommodation coefficient, the lower the flying height and pitch angle. Positive pressure sliders are more sensitive to the accommodation coefficient than are negative pressure sliders. The typical discrepancy in flying height is around 10%. Also, it is shown that for positive pressure sliders the lower the flying height, the larger the discrepancy percentage.[S0742-4787(00)00402-1]