One-dimensional linear distortion similitude research on concentrator unit for SSPS

Abstract

The scaled-model thickness cannot be reduced by the same scaling factor as the length in similitude analysis of the space solar power station (SSPS) large-scale concentrator unit, resulting one-dimensional linear distortion. Thus, the complete scaling law is invalid, established by the traditional similitude analysis, reducing the prediction accuracy. To weaken the distortion effect, a chain separate similitude analysis method is presented to establish the distortion scaling law, thereby enhancing the prediction accuracy. First, a global scaling law is obtained based on dimensional analysis. Second, distortion model is formed by introduced a distortion coefficient, which allows for the global scaling law to be chain-separated into complete and partial similitude scales. Third, two sub-models of complete similitude and partial similitude are constructed respectively to weaken the distortion effect. Then, the scaling laws are established including complete and partial similitude, respectively. On this basis, the natural frequency distortion scaling law is derived. Finally, finite element models of the concentrator unit prototype and distortion model are developed to validate the suggested method. Through simulation analysis, the large-scale prototype first-order natural frequency predicted value is 28.34 Hz, while the theoretical value is 28.32 Hz. The prediction error of the first four orders’ natural frequency for the prototype is kept within 0.4%. Results indicate the proposed method can improve the accuracy by one order of magnitude compared to the existing methods, greatly weaken the distortion effect, and effectively solve the one-dimensional linear distortion problem.