Wind Excited Action around Tall Building Having Different Corner Configurations

Abstract

Aeroelastic instabilities are common in square or rectangular plan shape structures due to the development of powerful vortices by the rolling motion of the separated shear layers. Windward corner modifications such as corner cut, recession, rounded, and slotted help to reduce instabilities. Codal recommendations about common shapes like square, rectangle, triangle, and circular shapes are available in different international standards, but they did not provide the detailed analysis results for the different regular shapes with corner configurations. Although analysis was performed on various plan shapes of tall buildings using the computational fluid dynamics technique through k-ε turbulence model, a very small number of studies were performed on particular shapes with different corners having same plan area and height. The mean pressure coefficients of Model-A and Model-B were compared with various international standards and wind tunnel data, respectively, for validation, showing a nearly equivalent consistency; however, international standards consist of coefficients at 0° and 90° wind angles only. Wind effects on building shapes having different corners change the characteristics of the separated shear layer and reduce the downstream wake which helps to reduce drag and lift forces simultaneously. Recent study shows that the windward pressure distribution pattern is almost independent of building size and height. Therefore incorporation of corners in building helps to reduce the forces caused by extreme wind. A very large amount of numerical simulation data about wind pressure is generated, which can be used by the designer while designing such a building for wind load. Comparison have been made between buildings having different corners under same wind speed, and Model-D (round corner) performed very well against the wind.

Analysis of Wind Effects on Tall Buildings of Irregular Cross-Sections Using Numerical Simulation

“…[2] analyzed the properties of wind flow and the distribution of wind pressure on the surfaces of an octagonal-shaped building model. [3] studied the effects of wind on tall buildings using CFD simulation in various ways. [4] used CFD to analyze the interference effect of three identically tall square-plan buildings on the pressure at the faces of an octagonal-plan structure.…”

Wind Effects on Rectangular and Triaxial Symmetrical Tall Building Having Equal Area and Height

“…e accuracy of CFD simulation can be seriously compromised when wall function roughness modification based on the experimental data for sand grain roughened pipes and channels are applied at the bottom of the computational domain. Numerical studies are already conducted on the different types of the plan shape structure, such as Tian et al [34] on a rectangular shape, Gaur and Raj [35] on corner modification on a square and a plus shaped building, Raj et al [36], Keerthana and Harikrishna [37]on the "H" plan, Kumar and Raj [38] on an octagonal plan shape, Raj et al [39] obtained response of a square and a plus shaped building by varying wind loads, Gaur et al [40] studied the interference effect using CFD, Mukherjee et al [41], Sanyal and Dalui [42][43][44][45], Goyal et al [46] on the "Y" shape, Meena et al [47], Kumar and Raj [48] on the "L" shape, Raj and Ahuja [49], on the "+" shape, Sanyal and Dalui [50] on the rectangular shape having some modification, Meena et al [51] investigated the wind effects on the regular shaped structure having a rectangular plan with various corner modifications, Mallick et al [52] on the "C" shape, Amin and Ahuja [53] on the side ratio of a rectangular building, Amin and Ahuja [54] obtained response of a tall building against the wind load. e considerable outcomes after modifying the shapes of the structure are as the Strouhal number is not sensitive to the aspect ratio, flow reattachment of the separated shear layer in the corner cut model present suction into corners, which is further caused in the reduction of drag, interference position of the building is highly effecting principal building pressure distribution, the length/width (side ratio) makes changes into the upwash, downwash, and the stagnation zone on upstream of flow, shielding effects were the main factors which is controlling the spacing between the buildings, highest wind velocity is obtained at the edges of the windward side and minimum at the leeward side, maximum suction is observed at the corner of the building, it is important to give due consideration for suction on the corner region, by increasing the L/W ratio horizontal force coefficient and overturning moment coefficient increases by the significant amount, the model with the rounded corner is best to reduce wind loads and overturning moments, in comparison of the chamfer corner, rounded corner are efficient in reducing the wind load, deflection is observed due to the presence of vortices in the wake region of buildings, the accuracy of the k-ε turbulence m...…”