火焰筒结构局部热屈曲分析方法

Local thermal buckling analysis method of combustor liner

根据局部热屈曲的失效机理,考虑局部温度和压应力水平两个热屈曲主要因素,从以应力函数和挠度函数为变量的受热板控制方程出发,推导出薄壁结构热屈曲失稳边界的判据表达式.依据确定的热载荷和设计的压力载荷,确定火焰筒结构的局部热屈曲危险部位,并将子模型技术引入到热屈曲分析中,确定危险部位的临界温度和临界压应力,以此对火焰筒结构进行局部热屈曲判别.通过工程实例的初步验证,计算与试验结果吻合良好,对火焰筒结构设计具有重要的工程应用价值.

The discriminant of thin-wall structure thermal buckling instability boundary was derived from governing equations of plates in which the stress function and deflection function are two variables, and the two buckling factors which are local temperature and compressive stress were included in the equations. Then, the gained thermal load and design pressure load were used to capture the dangerous place of eombustor liner through static analysis considering thermal buckling instability factors. The critical temperature and critical compressive stress which are required parameters of local thermal buckling discriminant were calculated with finite element method （FEM） and sub-model technique. Finally, a judgment of local thermal buckling was performed through the discriminant. In order to verify the method, the resuhs of certain combustion chamber calculated by the method were compared with the experimental data. It is concluded that the local thermal buckling analysis method is accurate and effective.