Application of screens and trips in enhancement of flow characteristics in subsonic wind tunnels

Subsonic wind tunnel experiments were conducted to study the turbulence level in the test section. Measurements were performed by introducing trip strip and/or damping screens on the flow field. The results indicated that the introduction of trip strips not only reduced the turbulence intensity compared to cases without it, but also flattened the variations. Further, the experiments which investigated the impact of the damping screens indicated a similar reduction in turbulence intensity; the pattern, however, remained the same. Furthermore, the results for cases wherein both trip strips as well as damping screens were placed on the contraction and in the settling chamber, respectively, showed that turbulence intensity was even more reduced than in previous cases. It is believed that the combination of several damping screens with the trip strip could be a sound method for turbulence reduction in subsonic wind tunnels. © Sharif University of Technology, February 2010.