Effect of Turbulent Modeling on Computed Wind Pressure Load over Cooling Towers with Base Structures and Comparison with VGB Guide-line

The wind pressure is one of the important loads on cooling towers which can be computed via numerical solution of the wind flow. In this paper, the effects of turbulent modeling on accurate computations of wind pressure on a cooling tower with base structure are investigated. For this propose, the results of a finite element flow solver using various commonly used turbulence models are compared with the reported laboratory measurements on a small scale physical. Having chosen the most suitable turbulence model, the effect of considering the geometrical features of the base structures supporting the louvers on formation of pressure fields over the external surface of a cooling tower in actual scale (designed for the KAZERUN combined cycle power plant) is investigated. The computed results of this case with and without base attachments are compared with the wind loads which are suggested by the VGB guidelines. The comparison of the results shows that, the pressure distribution trend (particularly in the rear side) slightly differs for various elevations. Furthermore, considering the effects of base structures of the cooling towers ends up with computed pressure distribution different from the pressure distribution suggested VGB guidelines, particularly in lower parts of the tower.