CFD Analysis for Wind Flow Characteristics of Varying Cross-Section Tall Building Using ANSYS

Abstract

Tall buildings are being developed at rapid rates owing to the need for optimization of space for increasing urban crawl. Tall buildings having simple cross -sections are designed using IS 875 (Part 3) -2015, however there is a lack of set of codal provisions for complex cross -section shapes. This study has been undertaken to interpret the wind flow characteristics of an isolated tall building (Model A) utilizing CFD (Computational Fluid Dynamics) and k -ɛ turbulence model in ANSYS: CFX (Analysis of Computational Fluid Dynamics program). Model A is 192 m in height having two types of cross sections -plus and square; each of height 96 m. Wind of intensity 10 m/s is incident on it at four incidence wind angles 0°, 30°, 60° and 90°. Pressure contours obtained on simulation indicate that for incident wind angles 0° and 90°, all lateral faces of the Model A (proposed design model) show similar pressure impact. Whereas, for incident wind angles 30° and 60°, wind ward faces (A and C) show decreased pressure impact with respect to 0° case. Vertical streamlines depict a recirculation zone at one -third the height of Model A for incident wind angle, 30°. Whereas, horizontal streamlines indicate the occurrence of vortex formation in the wake region of the building for incident wind angles, 0° and 90°.