Numerical Simulation Of Blocking Effect In Model Test

Wind load is very important to buildings and as a horizontal load,it is indispensable to the design of building structures.With the rapid development of the global economy,China is carrying out large-scale civil engineering constructions.A large number of high rise civil buildings,industrial buildings,long span bridges and large span buildings were built and put into operation.In this environment,wind load plays an increasingly important role in structural design.In some case,it even has become the control load.Wind load has been numerically calculated from the basic research into the practical application at present.On this paper,international common wind engineering standard building model of CAARC proposed by Commonwealth Advisory Aeronautical Research Council in 1969 was simulated and calculated the pressure characteristics in the atmospheric boundary layer by limited volume software Fluent14.0.According to the calculation of the standard model,the law of wind pressure distribution and the value of wind pressure on the structural surface were obtained and compared with the results of the corresponding wind tunnel test,which ensured the reliability and effectiveness of the numerical simulation method and made reference and prediction for the wind tunnel test.The main contents of this paper were as follows:(1)Based on the research results of wind tunnel test and numerical simulation of existing buildings,the feasibility and effectiveness of building wind load are verified by numerical simulation.The obstruction effect common to the wind tunnel and the numerical simulation wind tunnel were expatiated.The key problems of blocking effect and the method of avoiding obstruction effect in numerical simulation were presented.(2)The numerical simulation of software Fluent 14.0 was carried out to analyze the influence of the wind loading on the surface of the same building under different Reynolds numbers,different cross-sectional shapes and different wind direction.(3)In the Fluent14.0 software,the influence of different obstruction degree on the wind pressure characteristics of the building model was analyzed under the condition of 7m/s,14 m/s,28m/s three kinds of wind velocity.Deviation of the results caused by blocking effect was corrected.Based on previous empirical formula,the adjustment factor was considered,which made better correction of the results caused by the blocking effect.