0.6m连续式跨声速风洞真空系统设计及性能分析

Design and Performance Analysis of Vacuum System in the 0.6m Continuous Transonic Wind Tunnel

为了将中国空气动力研究与发展中心0.6 m连续式风洞最低总压运行能力由20 kPa拓展至5 kPa,提高其降速压试验能力,采用罗茨-水环泵组合抽气机组对原水环真空系统进行提升。建立了包含机组抽气效率、管路流导以及漏气率在内的风洞低真空连续抽气计算模型,与风洞试验结果进行了比较,分析了影响系统抽气性能的主要因素。结果表明:罗茨-水环组合机组是实现连续式风洞5 kPa总压的有效途径;计算模型获得的风洞抽气降压曲线与试验测试值偏差小于10%,可用于低真空系统性能分析;设计风洞低真空系统时,宜控制抽气主管平均流速在30 m/s左右,在最低工作压力下应保证有效抽气量相对漏气量有合理余量以提高运行效率。研究结果可为类似风洞真空系统设计及方案评估提供指导。

The upgrading of the vacuum system of 0.6m continuous wind tunnel in CARDC has been completed by replacing water-ring pumps with the combination of roots and water-ring pumps, expanding the lowest operating total pressure from 20 kPa to 5 kPa. A mathematical simulation model considering pump’s efficiency, pipe pressure loss and leakage rate is proposed to predict the pumping time from one pressure state to another for the wind tunnel. Results from this model are validated by experiments, and the main factors affecting the pumping time are confirmed. The results show that: the combination of roots and water-ring vacuum system is an effective way to achieve the 5 kPa total pressure in the continuous wind tunnel;the model can be used to analyze the performance of low-vacuum system considering that the deviation between model and test result is less than 10%;the average flow velocity in the pipeline should be controlled below 30 m/s and reasonable margin should be reserved for the actual pumping volume to improve operation efficiency, especially in the lowest pressure. This research can provide guidance for the design and evaluation of the vacuum system for a similar wind tunnel.