Study On Characteristics Of Wind Load On Double-skin Facade Of Buildings With Typical Shapes

For the double-skin facade has good performance of ventilation and lighting, it can improve greatly the comfort of buildings and also save energy. The double-skin facade is applied more popular to buildings as people pay more attention to the comfort of buildings and the protection of environment. For the buildings with double-skin facade, there are three surfaces subjected to wind pressure due to the airflow between the double-skin facades. Those are the outside and inside surfaces of the external skin facade and the outside surface of the internal skin facade, which make the wind loads acting on the double-skin facade become complicated. Few codes are presented to regulate the wind loads on double-skin facade in most countries. Consequently, the studies of the pressure distribution on double-skin facade have vital academic significance and engineering value.Systematic investigation methods of wind tunnel tests, numerical simulation and theoretical analysis had been adopted to study the characteristics of wind loads, the probability distribution of fluctuating wind pressures and some factors affecting the internal pressure of double-skin facade.In aspect of experimental research, according to rectangular and cylindrical tall building, a series of double-skin facade models with various separations were designed and multiparameter (opening areas and spacing of corridor) comparison wind tunnel tests were conducted. The spatial distribution characteristics of wind pressure on the double-skin facade were analyzed, and then the influce of wind pressure on the three surfaces of double-skin facade by the opening ratio of the external skin facade and the spacing of corridor were studied. The correlation coefficients of internal-external pressure, the probability distribution of fluctuating wind pressures and the peak factors of double-skin facade were explored.Base on the discussion of parameters affecting the internal pressure acted on the corridor, the theoretical method for estimating mean internal pressure coefficient was introduced emphatically, the theoretical results agree well with the test ones, and then the space distribution characteristic and mechanics of internal pressure were expounded.Finally, wind loads on double-skin facade buildings with rectangular and cylindrical shape were computed by CFD method, comparisons between the results from the wind tunnel test and the numerical simulation were performed to know the accuracy of the simulation. The advanced k-εturbulence model was used to discuss the interference of the outflow air from the corridor on the external flow around the building and the influence of surface roughness on the space distribution of internal pressure.