Abstract: This paper presented a highly realistic simulation of the tree swaying in the wind method. The method uses I= system to build the finite element model of tree. Perlin noise function was introduced to establish wind model which has natural wind' s 1/ f fluctuation characteristics. Mechanics of materials beam motion model was used to simulate branches bent by the wind. This paper analysed in detail the trees block to wind: branch block and leaf block, that is "fluid-structure interaction" phenomenon between wind and trec,especially in dealing with the process of branch block, using flow around circular cylinder in the model. The results show that this method gets realistic effects on a tree swa- ying in the wind, and the effect of real-time display can be achieved.

Key words: Tree, l/f fluctuations, Wind model, Fluid-structure interaction, Flow around circular cylinder