阻塞比对开口式风洞喷口风速测量方法的影响

Influence of Blockage Ratio on Nozzle Wind Speed Measurement Method in Open-Jet Wind Tunnel

摘要:

以1∶15的3/4开口回流式模型风洞为研究对象，通过放置不同比例大小的Ahmed body模型，采用试验和数值计算相结合的方法，研究阻塞比对于喷口法和驻室法这两种喷口风速测量方法的影响.结果表明：不同的阻塞比工况下，虽然驻室法测量误差稍大于喷口法测量误差，但驻室法对于修正系数的敏感度明显低于喷口法，即驻室法可使用更少的修正系数修正更多的工况，更易进行修正.

关键词:风洞试验; 数值仿真; 阻塞比; 喷口法; 驻室法; 误差修正

Abstract:

In this paper, the 3/4 open-jet closed circuit model wind tunnel with a ratio of 1∶15 was taken as the research object. By placing the Ahmed body model with different proportions, the combination of experiment and numerical simulation was conducted to study the influence of blockage ratio on nozzle wind speed measurement by using the nozzle method and the plenum method. The results indicated that, for different blockage ratios, the measurement error of the plenum method was slightly larger than that of the nozzle method, but the sensitivity of the plenum method to the correction coefficient was significantly lower than that of the nozzle method i.e., more working conditions could be corrected with fewer correction coefficient for plenum method, which meant that the plenum method was easier to be corrected.

Key words:wind tunnel experiment; numerical simulation; blockage ratio; nozzle method; plenum method; error correction