Chapters authored
Physical Models of Atmospheric Boundary Layer Flows: Some Developments and Recent Applications
Experimental studies on wind engineering require the use of different types of physical models of boundary layer flows. Small-scale models obtained in a wind tunnel, for example, attempt to reproduce real atmosphere phenomena like wind loads on structures and pollutant dispersion by the mean flow and turbulent mixing. The quality of the scale model depends on the similarity between the laboratory-generated flow and the atmospheric flow. Different types of neutral atmospheric boundary layer (ABL) including full-depth and part-depth simulations are experimentally evaluated. The Prof. Jacek Gorecki wind tunnel of the UNNE, Argentina, and the Prof. Joaquim Blessmann closed-return wind tunnel of the UFRGS, Brazil, were used to obtain the experimental data. Finally, some recent wind engineering applications of this type of physical wind models are shown.
Part of the book: Boundary Layer Flows
Wind Tunnel Experiments on Turbulent Boundary Layer Flows
The knowledge and experimental development of boundary layer turbulent flows is extremely important in applications related to the building aerodynamics, wind comfort, atmospheric dispersion, and even aeronautics. The Aerodynamic Laboratories of the UFRGS and UNNE have been making joint activities related to wind engineering such as those mentioned earlier for more than 25 years. In this work, a compilation of different experiments on turbulent boundary layer flows realized in these both laboratories is carried out. The characteristics of flows that develop on a smooth surface of the wind tunnel are experimentally evaluated. Then, reduced-scale models of atmospheric boundary layer flows are analyzed including the effects of turbulence generators and surface roughness. Special attention on the behavior of the turbulent parameters in the case of experimental studies using low mean velocity is paid. Finally, some comments referring to recent studies on thermal effects in turbulent boundary layer flows and the development of reduced-scale models of convective flows are included.
Part of the book: Boundary Layer Flows