| The high tower is an important equipment in industrial production, In recent years, The number of the towers which have the large ratio of height and diameter is increasing quickly.Wind load is an important load of tower structure, it is a typical dynamic load, The wind load and the tower structure’s interaction can lead to fluid-structure coupling effect, and cause the high frequency vibration and large deformation of the tower structure, So the reasonable structure of tower has important influence on the wind-resistance of the tower. This paper took the thermal power plant’s tower equipment as the research object, In view of vibration problem of the tower in the strong wind, and put forward three kinds of improved tower structure, analyzed the wind flow field around the tower structure,and Research the tower structure and the improved tower structures’ vibration characteristics that considering the interaction between the wind and the tower structure, The main contents are included as follows:Firstly, built the finite element model of the original tower structure based on Design Modeler module of ANSYS Workbench platform, put forward three kinds of improved tower structure model according to the engineering application, compared and analyzed the difference of the original tower structure and improved the structures’ the natural frequency and vibration mode, analyzed the deformation and stress of the original tower structure and the improved structures under the static wind load. The results show that the improved structures of the previous two order natural frequency and vibration model are closed to the original tower, and the numerical have first increase then decrease with the increase of reinforcement height, the improved structures of the after fourth order natural frequency is bigger than the original tower, and grow larger with the increase of reinforcement height; the improved structures have a smaller deformation than the original tower under the wind load,and the towers’ deformation decrease gradually with the increase of reinforcement height.Secondly, under the different return period wind speed, the flow field was simulated around the tower in Fluent, obtained the lift coefficient curves, The frequency analysis was carried out on the lift coefficient curve in Matlab, compared with different heights’ theory of vortex shedding frequency, and analyzed the pressure and velocity distribution around the tower. The results show that the amplitude of lift coefficient is the largest at 10 meters high,the vortex shedding frequency grow larger with the increase of the height, and when the wind speed increases, the lift coefficient of amplitude and frequency get bigger; On the windwardside of the tower, pressure distribution is symmetrical, and on the leeward side of the tower,pressure distribution is asymmetric under different wind speed and heights.Thirdly, based on SYTEM COUPLING module of the ANSYS Workbench, the different tower structures’ two-way fluid-structure interaction was simulated, Through the comparison and analysis, get the different towers’ along wind and cross wind vibration under different return period wind speed. The results show that the improved structures’ vibration average value of the maximum displacement and maximum stress each time step during the whole show are smaller than the original tower, The reinforced structures improve the overall vibration of the tower; The improved structures and the original tower have the same vibration frequency along wind, and improved structures’ along wind vibration amplitude is smaller than the original tower structure; The improved structures and the original tower’s crosswind vibration frequency haven’t obvious regularity, however, on the whole, the crosswind vibration amplitude of the improved structures is smaller than the original tower, In the engineering application, we can choose the different height of reinforced structure according to the local wind environment. |
PDF Full Text Request