CFD Study of Flow Characteristics and Pressure Distribution on Re-Entrant Wing Faces of L-Shape Buildings

Abstract

The purpose of this research is to investigate the wind flow pattern and pressure distributions on the re-entrant wing facades of an irregular L-cross sectional shape model over the range of wind incidence angles. Computational simulation with ANSYS (CFX) solver has been used for the study on model of the building of cross-sectional area 300m2 and height 50m at a length scale of 1:100. ANSYS (CFX) is a finite element modelling CFD program of pressure-based solver technology suitable for low Mach No. (Ma) fluid flow. Homogeneous flow of steady wind with gustiness of 5% turbulence in boundary layer of atmosphere is taken for the study. Investigation has been conducted for a range of wind angle of attack from 0° to 180° @ 15° interval. The findings were confirmed by examining similar wind flow on a rectangular model of same cross-sectional area and height under same boundary conditions as applied to L shape model. The results were compared with the values given in various international wind design codes/standards. For a better understanding of the flow characteristics around the L shape model in terms of flow stagnation, flow separation, creation of wakes & vortices and reattachment of flow; illustrations of flow patterns around the model for certain specific wind incidence angles are presented. On the basis of study of surface pressure generated on the model envelope, coefficient of pressure on the re-entrant corner faces has been discussed. The pressure on these wing faces has been found critical between 75° & 180° wind incident angles.