涡轮导向叶片热冲击数值模拟研究

Numerical Simulation of Nozzle Guide Vane

关键词:  涡轮导向叶片  瞬态流/热耦合  热应力场  模态分析

Key words:  Nozzle guide vane  Transient flow/thermal coupling  Thermal stress field  Modal analysis

摘要:

研究热冲击作用下涡轮导向叶片的热应力及振动模态，旨在从热-结构影响角度揭示静子叶片损伤机理，对其热疲劳寿命分析及抗热疲劳设计具有重要意义。基于瞬态热/流耦合理论，采用有限元/边界元方法，实现某型航空发动机涡轮导向叶片在热冲击作用下的温度场计算，在此基础上求解出叶片的热应力及振动模态。研究表明，采用瞬态流/热耦合可以有效预测叶片的温度分布，其结果与试验误差为6%；依据计算所得热应力及模态振型，可以推断出叶片出现热损伤的位置，且与实验结果吻合较好；根据数值模拟结果，固有频率随温度的升高而下降，前六阶频率平均下降24.7%。

Abstract:

The study on thermal stress and vibration mode of turbine guide vanes under thermal shock，aiming at revealing stator vane damage mechanism from the perspective of heat-structure affected，has a great significance for thermal fatigue life analysis and the thermal design of guide vanes. Based on the theory of transient thermal/flow coupling，using Finite Element Method and Boundary Element Method，temperature field calculation of a certain type of engine turbine guide vane under thermal shock was achieved，in this case，the thermal stress and vibration modals of the guide vane has been solved. Studies have shown that transient flow/thermal coupling can effectively predict temperature distribution of the guide vane. Compared with the experimental data，the simulation results has error of 6%. According to the simulation results of thermal stress and vibration models，the guide vane thermal damage location can be inferred，and it was consistent with the experimental results. On the basis of numerical simulation，natural frequency decreases with the temperature and previous six order frequencies decrease by 24.7% on average.