Experimental and Numerical Investigation of In-line Standing Circular Cylinders in Steady and Turbulent Wind Flow

The wind pressure distribution on structures is an important parameter in terms of wind load calculation. Some wind effects, especially interference effects, are still the subject of research and experimental measurements in wind tunnels, but also in-situ. For the in-line standing circular cylinders EN standard gives only the wind force coefficient that is higher than the wind force for the stand-alone cylinder. The wind flow around in-line standing cylinders is based on distance between cylinders and their roughness and also on local wind velocities and neighboring structures. This paper deals with interference effects of air flow around the group of circular cylindrical structures. In this research, a series of parametric wind tunnel studies was carried out in BLWT Wind Tunnel in Bratislava to investigate the interference effects of in-line standing cylinders in steady and turbulent wind flow. In a steady flow in the front measurement area, we tested cylinders with smooth and rough surface at varying distance and angle of wind direction and for 10 different wind velocities from 9.6 - 19.7 m/s. The graphs of the external wind pressure distribution on the circumference of the cylinder for different wind speeds give us good information about behavior of in-line standing cylinders in steady wind flow. In a turbulent wind flow in the rear measurement area in BLWT, we tested three cylinders for different wind velocities and compared results for different positions on cylinder. Experimental results of wind pressure around cylinders were compared with CFD numerical analysis and EN 1991-1-4 standard We chose the finite volume method implemented into program ANSYS Fluent [1], which offers several turbulence models.