Design And Research Of Similar Dish CSP Steel Frame Rack Model In Wind Tunnel

Dish CSP rack with steel frame as the critical component of high power dish solar thermal power generation system, has the characteristics of complicated space structure, large concentrated area, large fuselage weight etc. Meantime, the structure of rack is sensitive to wind. Methods by using the wind tunnel test invert the mechanical properties of prototype structure which is an important means for the wind design of structure that large-scale、complex and open. But now the research of dish rack model similar problems is very scarce. Therefore, based on the model similarity theory, combining with numerical simulation method, around the problem of similarity dish rack of prototype and model are studied, which is particularly urgent and important significance.First, according to the structural characteristics and operating characteristics of each component of dish rack, analyzing the similarity criterion mode based on the similarity theory, deducing the similarity parameters which is must satisfy for static and dynamic model of rack, getting a series of the similarity relations between prototype and model of rack: the similar geometry design for rack is mainly based on numerical wind tunnel blockage effect to achieve, flow similarity relation mainly satisfy the Euler number similar requirements and give up the Reynolds number similarity condition, and the frame of static and dynamic similarity relation is similar to the rigidity and quality as the core.Secondly, based on the block effect theory of wind tunnel test, CFD simulation software is used to build the wind tunnel river basin of different proportion of rack, analyzing the influence mechanism of blocking ration to the average wind load characteristic of the rack. Results show: blocking effect to the average wind pressure and distribution for windward and leeward of condenser is different, especially for leeward. The best blocking range of the rack model is 2.76 percent to 3.10 percent which can provide the basis of the selection of geometric scale ratio for rack.Finally, determining the geometric scaling ration of rack model is eight by according to the best blockage range and the spatial dimensions for wind tunnel test section, and accordingly the parameters similar design of each component structure, establishing the frame prototype and Shrinkage ratio rack finite element model based on ANSYS software, through the numerical simulation of static and dynamic characteristics, comparative analysis of the stress, self similarity characteristics of vibration parameters, displacement on each frame. Results show: both on the displacement and stress distribution as well as various order formation are basically identical, the fundamental frequency of space truss structure similar to a larger error, it should increase the bending stiffness of lateral model of component, similarity degree of the whole machine model and prototype is obviously lower than the grid structure, But the similar error range in 5% of the controllable range, this can also verify the correctness of the design of the frame model and the prototype on the similarity relation.