The performance bottleneck in high-rotational-speed turbomolecular pumps (TMPs), wherein a significant increase in rotational speed does not lead to a noticeable increase in pumping speed, can be attributed to a mismatch between the traditional straight blade structure (TSBS) and high rotational speeds. Therefore, based on the theory of molecular gas dynamics, a gas molecular transport model incorporating twisted stator blade rows (TSBRs) was established. Utilizing the Monte Carlo (MC) method, a simulation calculation program was developed and validated in previous research. Taking structural parameters of the first four stages of a TMP available in the laboratory as an example, research on the necessity of TSBRs in TMPs was conducted. Our research findings indicate that increasing the probability of collisions between gas molecules and the lower surface is beneficial to improve pumping speed. Gas molecules incident on stator blade rows are no longer evenly distributed, exhibiting a trend of being sparse in the middle and dense at the edges. The maximum pumping speed coefficient and maximum compression ratio of the four-stage combined blade rows with TSBRs increased by 71.86% and 15.14%, respectively. Our research findings confirm the necessity of incorporating TSBRs and also provide direction and theoretical guidance for the structural optimization of TMPs.
Zhao et al. (Thu,) studied this question.