Experimental study of turbulent wind flow over arc roofs: an ancient simple way to low energy buildings
محورهای موضوعی : فصلنامه شبیه سازی و تحلیل تکنولوژی های نوین در مهندسی مکانیک
Farhad Raeiszadeh
1
,
Mehdi Jahangiri
2
1 - Energy Research Center, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
2 - Energy Research Center, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
کلید واژه: Reverse flow, Recirculation, Arc roof, Hot wire, Separation.,
چکیده مقاله :
In hot, dry areas around the world, buildings are planned to shield against strong winds and to offer natural cooling during the summer. Many of these structures have curved or domed roofs, like arcs, vaults, or semi-circles. This paper presents an experimental study of air flow over arc roofs mounted over a flat surface with various diameters (80, 120, and 200 mm) at different flow velocities (5, 10, and 15 m/s). For this aim, models of half circle shape with the same length and different diameters have been made and installed in a subsonic wind tunnel. Using a vertical hot wire probe, measurements were conducted to analyze flow characteristics, which included mean flow velocity directions, root mean square values representing turbulent fluctuations, and the skin friction coefficient. These measurements helped in establishing the fluid pattern over the vault. Also, it was found that with increasing Reynolds number, fluid characteristics such as separation angle, recirculation length are increasing and location of maximum velocity remains almost constant. Results of experimental measurements are compared with flat roofs data and better thermal performance of arc roofs is observed.
In hot, dry areas around the world, buildings are planned to shield against strong winds and to offer natural cooling during the summer. Many of these structures have curved or domed roofs, like arcs, vaults, or semi-circles. This paper presents an experimental study of air flow over arc roofs mounted over a flat surface with various diameters (80, 120, and 200 mm) at different flow velocities (5, 10, and 15 m/s). For this aim, models of half circle shape with the same length and different diameters have been made and installed in a subsonic wind tunnel. Using a vertical hot wire probe, measurements were conducted to analyze flow characteristics, which included mean flow velocity directions, root mean square values representing turbulent fluctuations, and the skin friction coefficient. These measurements helped in establishing the fluid pattern over the vault. Also, it was found that with increasing Reynolds number, fluid characteristics such as separation angle, recirculation length are increasing and location of maximum velocity remains almost constant. Results of experimental measurements are compared with flat roofs data and better thermal performance of arc roofs is observed.
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