The influence of a 90° bend on the characteristics of the flow in a low-speed wind tunnel is investigated with CFD (Computational Fluid Dynamics). CFD validation is performed based on published experimental data. The investigated bend is designed to preserve a uniform velocity inlet profile and a low turbulence level. The influence of bend curvature is assessed. Moreover, the effect of the presence, the number and the spacing of guide vanes is investigated. Two turbulence models are evaluated in the numerical simulations. Bends with a weak curvature and guide vanes are found to perform best in preserving a uniform velocity inlet profile. Comparing guide vanes with equal and variable spacing, the latter results in better flow uniformity in the centre of the duct, downstream of the bend, but not at the outside. A considerable increase in turbulence level is noticed for all configurations investigated. The turbulence has a significant anisotropic character indicating the need for turbulence models that can account for anisotropy in this type of studies.
|Title of host publication||Proceedings of the12th International Conference on Wind Engineering (12ICWE), 1-6 July 2007, Cairns, Australia|
|Editors||J. Cheung, B. Melbourne|
|Place of Publication||Cairns, Australia|
|Publisher||Australasian Wind Engineering Society|
|Publication status||Published - 2007|
|Event||conference; 12th International Conference on Wind Engineering (12ICWE); 2007-07-01; 2007-07-06 - |
Duration: 1 Jul 2007 → 6 Jul 2007
|Conference||conference; 12th International Conference on Wind Engineering (12ICWE); 2007-07-01; 2007-07-06|
|Period||1/07/07 → 6/07/07|
|Other||12th International Conference on Wind Engineering (12ICWE)|
Defraeye, T. W. J., Moonen, P., Blocken, B. J. E., & Carmeliet, J. (2007). Numerical analysis of flow in a 90 degrees bend for a low-speed wind tunnel. In J. Cheung, & B. Melbourne (Eds.), Proceedings of the12th International Conference on Wind Engineering (12ICWE), 1-6 July 2007, Cairns, Australia (Vol. 2, pp. 1455-1462). Australasian Wind Engineering Society.