WIND TUNNEL PRESSURE MEASUREMENT STUDIES ON A TALL BUILDING WITH ELLIPTIC CROSS-SECTION: EFFECT OF ANGLE OF WIND INCIDENCE

S A Afreen, A Abraham,S Selvi Rajan, Nagesh R Iyer, Sanya Maria Gomez

Abstract: Wind tunnel pressure measurement studies were carried out on a rigid model (geometric scale 1:300) of a tall ellipticbuilding having minor axis of 100mm (b),major axis of 200mm (d) and height (h) of 700mm, under simulated open terrain in a Boundary Layer Wind Tunnel (BLWT) facility available at CSIR-SERC, Chennai. The measurement of pressures were made using 8 pressure sensors for 12 different angles of wind incidence, „?"ranging between 0°(wind normal to minor axis)and 90°(wind normal to major axis). Based on the analysis, mean pressure coefficients, mean drag/lift force and torsion coefficients were obtained corresponding to reference pressures at the respective measurement levels. It is observed that the evaluated values of mean drag force coefficients increased with change in angles of wind incidence from 0° to 90°. The evaluated values of mean lift force coefficientsincreased with change in angles of wind incidence from 0° up to 40? and beyond which itdecreased. The evaluated values of meandrag forcecoefficients were compared with the values reported in Codes of Practice viz. IS: 875 (Part 3) and AS-NZS 1170.2. The evaluated values were found to be comparablewith the values reported in IS: 875for ? = 90° and inASNZSfor ? = 0°

Keywords: Boundary Layer Wind Tunnel, Tall Elliptic Building, Angles of Wind Incidence, Mean Pressure Coefficients, Mean Drag/Lift Force Coefficients, Correlation Coefficients

DOI: https://doi.org/10.15623/ijret.2015.0425056