STABILITY OF COOLING-TOWER SHELL WITH MODIFIED WIND PRESSURE COEFFICIENTS

The stability analysis of natural draught cooling tower shell subjecte d to nonaxisymmetric wind pressure has been carried out using finite r ing elements. In this investigation, concept of a local enhancement of wind pressure coefficients at the top-in addition to the usual variat ion of wind pressures with height-has been newly introduced. Justifica tion for the use of such modified wind pressure coefficients has been presented. By considering the modified distribution of wind pressure c oefficients, a parametric study has also been carried out to assess th e influence of top ring stiffener, gradual thickening at shell bottom edge, and vertical cracking due to thermal gradient on the buckling be havior of natural draught cooling tower shells. Guidelines are furnish ed for choosing dimensions of the top ring stiffener to avoid top edge buckling.