Stability of Cooling Tower Shell with Modified Wind Pressure Coefficients

Abstract

The stability analysis of natural draught cooling tower shell subjected to nonaxisymmetric wind pressure has been carried out using finite ring elements. In this investigation, concept of a local enhancement of wind pressure coefficients at the top—in addition to the usual variation of wind pressures with height—has been newly introduced. Justification for the use of such modified wind pressure coefficients has been presented. By considering the modified distribution of wind pressure coefficients, a parametric study has also been carried out to assess the influence of top ring stiffener, gradual thickening at shell bottom edge, and vertical cracking due to thermal gradient on the buckling behavior of natural draught cooling tower shells. Guidelines are furnished for choosing dimensions of the top ring stiffener to avoid top edge buckling.