基于橫风非定常的CRH_6横截面优化研究

Optimization research on cross-section of CRH_6 by unsteady aerodynamic characteristics under crosswind

结合Lisp语言参数化建模和列车空气动力学横风非定常理论,对高架上运行的CRH_6型城际动车组横断面进行优化研究。在对正交试验的参数化模型划分网格的基础上,进行充分的横风定常计算,进行非定常计算记录监测数据,研究列车周围的非定常流场特性,对数据进行时域和频域特性的分析,得到优化方案。研究结果表明:定常横风作用下,列车气动力及周围流场都呈现明显的非定常特性,并有周期性;非定常主振频率与来流横风风速呈线性递增关系,在0～3 Hz范围内;综合考虑倾覆力矩的最大值和幅值对列车运行安全的影响,最终确定CRH_6横断面优化结果。

Combined parametric modeling based on Lisp language and unsteady aerodynamic theory of train under crosswinds,cross section of CRH6 intercity EMU which is common running on an elevated bridge is optimized.On the basis of orthogonal test,parametric models are meshed;firstly steady calculation under crosswind is fully simulated,and then unsteady calculation is carried out;monitoring date is recorded to research the unsteady flow field characteristics of the train around;finally,optimization results are got by the data of time domain and frequency domain characteristics.The results show that:under steady cross-wind effect,train aerodynamics’force and flow field around are all showed significantly unsteady characteristics,and cyclical;the relationship between unsteady main vibration frequency and flow cross-wind wind speed is linearly increasing,whose range is between 0 to 3 Hz;considering the operating safety effect of the train by the maximum and the magnitude of overturning moment,the final cross-section optimization results are determined.