Study of Wind Loads on Free-Standing and Closely Spaced Hyperbolic Cooling Towers

Abstract

Introduction. The construction of cooling towers has always been and remains a pressing issue in today's world. Wide spreading of cooling towers is necessary for power industry. The problem lies in the allowable location of a set of hyperbolic cooling towers at a premises of a single fuel-and-energy facility. The aim of the present study is to investigate the wind pressure distribution on a cooling tower having the shape of a single-cavity hyperboloid of rotation and the cross-interference of the closely spaced cooling towers. To achieve the set forth aim the following objectives are being solved: the finite-element modeling of a free-standing and several closely spaced structures, the analysis of the wind pressure isofields at different elevations and the comparison of the results with the currently valid standards.Materials and methods. The object of the study is the hyperboloid type cooling towers of total height 53.3 m. The analysis is carried out with the help of the three-dimensional finite-element modeling in the CFX module of the verified ANSYS software package. The k-epsilon turbulence model is used. For simplification, the wind speed is assumed constant along the structure’s height. The shells in the shape of a single-cavity hyperboloid including the airspace are specified by a parametric equation, which is modeled by using the solid finite elements in the form of tetrahedrons. The surface of the shells is assumed to be perfectly smooth. Besides finite-element analysis, the calculation of the interference factor is made according to the standards currently valid for reinforced concrete cooling towers.Results. The results of wind pressure distribution on free-standing and closely spaced cooling towers were obtained. The data on the wind pressure isofields at various elevations at various locations of tower structures was given.Discussion and conclusions. Upon comparing the obtained results with the currently valid SP 20.13330.2016 «Loads and actions» and SP 340.1325800.2017 «Reinforced concrete and concrete structures of cooling towers. Design rules» it was found that the distribution of wind pressure along circumference depends on the height, which had not been taken into account in the regulatory documentation. The analysis of cross-interference of the closely spaced cooling towers was carried out and it was demonstrated that in the currently valid standards the interference factor had been greatly overestimated.