| Solar tower has high aspect ratio,and its vortex-induced resonance wind velocity is much lower than the design wind velocity,so vortex-induced resonance with obvious amplitude is prone to occur.The equivalent static wind load of the structure will be greatly increased without vibration reduction measures.In addition,the maximum vibration amplitude of top collector structure is limited to ensure the solar energy reflected by mirrors can be accurately absorbed.Therefore,it is necessary to take effective measures to control its vibration.Tuned liquid damper(TLD)is a commonly measure to reduce wind-induced vibration of structures.At present,the research methods of TLD are mainly theoretical analysis and field measurement.In view of the difficulty in designing tiny TLDs in small-scale models,it is difficult to adopt wind tunnel test research methods.In this paper,the parameter optimization of the aero-elastic model of the solar tower was firstly carried out;a tiny-TLD design method that can be used in small-scale model wind tunnel test was proposed,and the modal parameters of multiple tinyTLDs were identified;based on a 243 m high solar tower the aero-elastic model wind tunnel test method was used to study the vibration reduction effect of TLD on the wind-induced vibration of the solar tower.The main work content and results are as follows:(1)Based on the design method of aero-elastic model of solar tower proposed in the literature,the main structural parameters of the aero-elastic model were optimized.Taking a solar tower as the research object,the ANSYS software platform is used to establish a finite element model,and the dynamic characteristics of the prototype structure are analyzed to obtain the design target parameters;through analysis,the structural design of the aero-elastic model was proposed to optimize the layout of the core beam channels and adjust the thickness of the collector chassis to overcome the shortcomings in the original model;the wind tunnel test model of the solar tower was designed and produced;the results of dynamic characteristics test show that expected simulation effect can be achieved by the model,which can adopt to therefined wind tunnel test research;(2)According to the calculation formula and equivalent mechanical model of the liquid sloshing parameters of the cylindrical TLD,the optimal structural parameters of TLD for the solar tower model,including mass ratio,damping ratio,frequency ratio and others were calculated;a tiny-TLD that can be used for modal parameter identification and wind tunnel test was designed and produced;modal parameter identification tests were carried out on tiny-TLDs with different inner diameters,and the actual values of frequency and damping were obtained;the experimental values were compared with the theoretical values to verify the applicability of the theoretical equation of liquid sloshing in small-sized containers,and the research parameters that can be realized in the TLD vibration damping wind tunnel test were selected;(3)The dynamic characteristics of the solar tower aero-elastic model were debugged,and the similarity ratio of the solar tower wind tunnel test in the liquid-free state was obtained;The wind tunnel tests of the solar tower before and after the theoretical optimal TLD was installed were conducted,and the evaluation indexes based on the root mean square of the response of the model across the wind direction were defined which are used to evaluate the TLD vibration reduction effect;the test results prove that the TLD vibration reduction rate in the vortex wind velocity range can reach 50%,and it is about 20% under the design wind velocity;TLD vibration damping wind tunnel tests with different liquid frequencies,qualities,and installation locations were carried out,and the influence of each TLD design parameter on the vibration damping effect was studied,and the importance of parameter of TLD design was analyzed. |
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