Numerical determination of drag coefficient for guyed mast exposed to wind action

• Published in: Engineering structures 2014-03, Vol.62-63, p.98-104
• Main Authors: Pezo, Milada L., Bakić, Vukman V.
• Format: Article
• Language: English
• Subjects: Applied sciences; Building structure; Buildings. Public works; CFD; Climatology and bioclimatics for buildings; Computational fluid dynamics; Construction (buildings and works); Drag coefficient; Drag coefficients; Exact sciences and technology; Fluid flow; Guyed mast; High rise structure; Lattices; Masts; Mathematical models; Numerical prediction; RANS; Stresses. Safety; Structural analysis. Stresses; Turbulence; Turbulent flow
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2014.01.025

•We determine the drag coefficient for lattice structure.•We did CFD numerical simulations of flow around one segment of the mast.•Geometry is simplified by only six cylinders connected to one volume.•We used standard k–ε, RNG k–ε and Reynolds stress model to determine flow field.•We compare these results with available experimental results. Guyed masts are used for meteorological measurements, in the telecommunication industry for wireless communication or for power transmission. For a guyed mast, wind load is the main factor affecting the stability of the structure. Determination of drag coefficient for lattice structure has been investigate in past. ESDU 81027 and 81028 and Eurocode 3 Part 3.1 give already some detailed information of the aerodynamic drag coefficient of lattice mast structures with circular members. Only certain types of lattice masts covers literature and codes tend to be conservative due to the necessity of simplicity. But in this study is presented numerical method using Computational Fluid Dynamics (CFD) to determine drag coefficient. The motivation for this study to investigate what CFD can offer or contribute to determine the aerodynamic drag forces of lattice mast structures as a supplement or even alternative to literature and codes. This would be in particular of interest for design engineers in the field of mast structures. Three-dimensional numerical simulations of one segment of a mast exposed to a wind action with three models of turbulence are performed. Three models of turbulence: standard k–ε model, RNG k–ε model and Reynolds stress model were used and compared with available experimental results. Drag coefficient was calculated based on integration surface pressure distribution, flow field and a reference area. Modeling was performed for four wind velocities, 10m/s, 20m/s, 30m/s and 40m/s. Reynolds number for those velocities corresponds to turbulence flow. Direction of inlet velocity is also variable, e.g. there are two angles of attack.