混合分段算法计算涡轮分子泵的压缩比

Novel Hybrid Segment Algorithm for Compression-Ratio Calculation of Turbomolecular Pump

为了进一步完善分子泵在整个流态区域内抽气性能的计算,本文分别对主要用于描述连续流体运动问题的连续流态方程法和主要用于描述分子流态问题的特征系数法进行了评价,两种方法在计算涡轮分子泵压缩比时有各自的适用范围。为了提高涡轮分子泵在过渡流态下压缩比的计算精度,本文在比较两种方法的计算精度和适用范围的基础上提出了混合分段算法。通过与实验值的对比,发现通过混合分段算法得到的最大压缩比与实验值的最大误差为10.5%,相对于连续流态方程法和特征系数法分别减小了34.0%和44.7%,证实了混合分段算法的适用性。该方法可以分析整个流态区域内涡轮分子泵的抽气性能,为分子泵压缩比的全流域计算提供参考。

A novel hybrid segment algorithm was proposed,by combining the two conventional schemes： the continuous flow equation and characteristic coefficient methods,to more accurately calculate the maximum compression-ratio of turbo-molecular pump in the transient flow. The original work was to figure out Knudsen number（ Kn）ranges,in which the two conventional algorithms give the maximum compression-ratios closest to the experimental data. For instance,herein the continuous flow equation and characteristic coefficient schemes work best in 0. 01 Kn 1. 5 and 1. 5 Kn 10 ranges,respectively. The maximum compression-ratio was measured and calculated in the novel and conventional algorithms. The largest discrepancy between the measured and calculated results in the new algorithm was 10. 5%,being 34. 0% and 44. 7% lower than those evaluated in the continuous flow equation and characteristic coefficient algorithms,respectively.