Numerical Simulation Of Wind Characteristics And Interference Effects On Complex Tall Buildings

With the development of tall building constructions the urban space configuration has become more and more complex in large cities. Wind-induced interference effects on tall buildings have increasingly been noticed by many investigators. Therefore it is highly necessary to make clear the law of interference effects of wind loads on tall buildings and accordingly find the corresponding wind-resisting means.Three main methods, site measurement, wind tunnel test and numerical simulation techniques are commonly used for the study of wind-induced interference effects on buildings. In this paper, the numerical simulation techniques are adopted to study the wind-induced interference effects on building complex which consists of two or three tall buildings. First the existing research achievement is presented. Then the fundamental equations and the corresponding numerical discretization and solution approaches for turbulent wind flow based on the averaged Navier-Stokes equation and k-ε turbulence model are established. As the first numerical example, a complex tall building model with neighboring tall building and without neighboring tall building is considered. The obtained numerical results are compared with those of the wind tunnel test and the validity and accuracy of the numerical simulation are demonstrated. Meanwhile the two turbulent model both Standard k-ε model and Realizable k-e model are compared and analyzed. Then the turbulent model of Standard k-s and non-equilibrium Wall Function which was used to solve the flow in the near regions is chosen to research the mean interference effects between two tall buildings. The values of mean interference factor (IF_m) at various configurations are presented. In addition, the orthogonal experimental method is introduced to design the experimental plan for studying the influence of the location, height, cross-section dimensions, velocity of wind, ground roughness, number of upstream building. The artificial neural network method is used to deal with the experimental data and the result is extended for the wind load codes.Finally, numerical simulation is performed to investigate the wind pressure distributions on the surface of a spherical tall building with and without curved annexes, the results obtained is applicable to wind-resisting design of this kind of structures.