Optimization of alongwind and crosswind force coefficients on a tall building with horizontal limbs using surrogate modeling

Abstract

SummaryFor tall buildings, values of wind force coefficients can be obtained from wind tunnel tests or Computational Fluid Dynamics (CFD). This paper is concentrated to analyze a set of CFD data and propose parametric equations for determining force coefficients in the alongwind and crosswind direction (Cfx and Cfy) of tall buildings with horizontal limbs. Initially, a parametric study is performed with CFD analysis considering RANS k − ε turbulence models keeping a constant plan area 22,500 mm2. The length and velocity scales are taken as 1:300 and 1:5, respectively. The required design parameters are obtained and used for fitting parametric equations. The CFD data are further utilized for training artificial neural networks of Cfx and Cfy. The results of CFD, ANN, and parametric equations are compared. The parametric equations are validated by employing a wind tunnel study. Finally, three optimization studies are carried out using a genetic algorithm (GA), of which the first two aim to present the maximum and minimum force coefficients considering single objectives. The third optimization is a multi‐objective optimization problem, carried out to simultaneously minimize and maximize the two orthogonal force coefficients. Pareto‐optimal design results are presented.