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

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.