Engineering Mechanics

Proceedings Vol. 31 (2025)

ENGINEERING MECHANICS 2025

Copyright © 2025 Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, Prague

 

Macháček M., Hračov S., Dejmal K.
pages 117 - 120, full text

This study presents the results of wind tunnel experiments on U-shaped beams with either solid flanges or flanges with 50% porosity. Aerodynamic drag and lift coefficients, along with pressure coefficient distributions on the beam surfaces, were evaluated and compared for both configurations. The findings demonstrate that flange porosity significantly affects the aerodynamic forces and flow around the U-beam. Across most angles of attack, the solid-flange beam exhibited higher drag than the porous-flange beam. However, within the range of approximately −11.5° to −5.5°, the porous configuration showed higher drag. Furthermore, at negative angles of attack, the lift force on the porous-flanged beam acted in the opposite direction to that on the solid-flanged beam. Finally, incorporating flange porosity reduced the magnitude of suction pressures on both the top and bottom surfaces of the U-beam.

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