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

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