Computational modelling applied to predict the pressure coefficients in deformed single arch-shape greenhouses

Abstract

In the calculation of wind effects on civil constructions, the pressure coefficients, which are usually obtained from specific standards or by tests of reduced models in wind tunnels, are essential, and these coefficients are commonly established from solid and undeformable models. For greenhouses covered with plastic film, due to the flexibility of this material, there are instantaneous modifications to the shape of the construction by the action of the wind. The aim of this study was to investigate the distribution of pressure coefficients on arched roof greenhouses displaced by the wind action transverse to the ridge. To achieve this goal, computational fluid dynamics (CFD) models were used to obtain the pressure coefficients in greenhouses with ratios between height and span of 0.3 and 0.6. The change in the shape of the greenhouse due to the displacements imposed by the wind showed that there were no relevant variations in the pressure coefficients of the wall zones. However, the effects of shape displacement were very significant along the extension of the arch of the roof, with a large reduction in the pressure coefficients mainly in the vicinity of the ridge.