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Testing a technique to generate low-frequency large-scale turbulence with the Wall of Wind : an experimental study

Haspels, M. (2014) Testing a technique to generate low-frequency large-scale turbulence with the Wall of Wind : an experimental study.

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Abstract:The Wall of Wind (WoW) is a large experimental setup, which is capable of simulating hurricane winds, located at the Florida International University (FIU). One of the goals of the Wall of Wind is to enhance full scale testing to gain a better understanding of the interaction between hurricane winds and structures like residential buildings, without dealing with scaling issues. Turbulence is one of the most important features of hurricane winds as these flows cause unsteady loads on structures. To model proper hurricane winds, the Wall of Wind should be able to generate a flow with turbulent structures comparable to the turbulent structures in the atmospheric boundary layer (ABL). The WoW is not yet capable of generating large-scale turbulent structures. A technique which possibly could be used to generate these turbulence structures with the WoW is tested in this study. A scale model of the Wall of Wind is built and the current setup used in the Wall of Wind is tested. The current setup contains a rectangular duct which has spires at the inlet and roughness elements on the floor. These spires and roughness elements must create a boundary layer which is similar to the ABL. It is concluded that the flow created by the current setup in the WoW definitely lacks large turbulent structures. Data on the ABL is obtained from experimental research which was done on the Silsoe Cube. The spires at the inlet are replaced by passive rotating vanes which are driven by the flow. The results showed that the vanes increase the generation of large-scale turbulence, however, the results are still not satisfying. Unfortunately, after a series of modifications and tests, no satisfying results were obtained. Hence it is concluded that replacing the vanes in the current WoW setup by passive rotating vanes does not significantly increases the generation of large scale turbulence. However, it is recommended to study the effect of controlled vanes, which can be set at a low frequency. This might generate larger turbulent structures.
Item Type:Internship Report (Master)
Clients:
University of Auckland, New Zealand
Faculty:ET: Engineering Technology
Subject:52 mechanical engineering
Programme:Mechanical Engineering MSc (60439)
Keywords:Turbulence, Silsoe Cube, Experiments, Wind tunnel, Wall of wind
Link to this item:http://purl.utwente.nl/essays/69340
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