An Investigation into Scale Open Jet Wind Tunnel Corrections through the use of CFD and Wind Tunnel Testing

摘要

Open jet wind tunnel corrections have been investigated for a number of years and the most comprehensive corrections that have been proposed were done so by Mercker and Wiedemann (1996). Their work presented the individual correction factors and the methods for implementing these corrections. Using these methods an investigation into the recently acquired wind tunnel at Coventry University was undertaken into the individual correction factors with the primary focus on finding the most influential factor.Using an automotive model presented by Wong and Mair (1983) these corrections would be investigated within the wind tunnel. Alongside this a validation study is undertaken on all the wind tunnel tests and the wind tunnel itself through the use of CFD. Previous studies presented by authors have looked into direct comparison of wind tunnel and CFD simulations and noted good agreement between results, however, a number of set-up issues can arise. By investigating a number of the wind tunnel’s properties a standardised model of the wind tunnel can be proposed for use within further CFD studies.With a number set-ups available it is possible to test one model with a variety of supporting apparatus (sting). This being the case it is important to have support apparatus that is well constructed and that does not interfere with the flow structure of the model in a detrimental way. The University has one particular apparatus that was made in-house. Through a number of tests it was found that this sting could influence the measured results in a large way therefore a method to improve the sting has been proposed. By implementing already available ideas it was found that the stings influence could be reduced by 90 counts.With the available data on the wind tunnel it was found that a CFD model could reproduce the investigated flow features to a level of reasonable accuracy. It is suggested, however, that for further validation, a more in-depth investigation of the wind tunnels flow properties such as span wise turbulence intensity and velocity profile is conducted.