周向收敛型动压式指尖密封是一种可用于航空发动机的非接触式柔性气封。根据周向收敛型动压式指尖密封的工作性能要求,提出密封性能优化数学模型。采用人工神经网络和遗传算法相结合的优化方法,通过建立反向传播(BP)神经网络确定设计变量与目标函数之间的隐含关系,再利用遗传算法对周向收敛型动压式指尖密封进行结构参数优化,获得了性能较优的周向收敛型动压式指尖密封结构形式。通过对具有优化结构的密封在转子启动工作阶段和转子受到周期性径向激励情况下的流固耦合动态性能仿真,验证了周向收敛型动压式指尖密封优化结果的有效性。本文工作可为设计性能良好的周向收敛型动压式指尖密封提供一定的理论依据。

A circumferential convergent hydrodynamic finger seal is a non-contact flexible gas seal which can be used in aero-engines. According to the working performance requirements of a circumferential convergent hydrodynamic finger seal, a performance optimization model is constructed. The optimized structure of the finger seal is studied by combining a neural network with a genetic algorithm. Based on a back propagation(BP) neural network, the implicit relationship between the design parameters and objective function is established, and then the structure of a circumferential convergent hydrodynamic finger seal with better performance is obtained by the genetic algorithm. By fluid-solid interaction calculation, the dynamic responses of the circumferential convergent hydrodynamic finger seal are analyzed in the process of rotor startup and periodical radial excitation. Compared with the circumferential convergent hydrodynamic finger seal which is not optimized in the dynamic behavior, the optimized finger seal exhibited better performance characteristics. This article can provide certain theoretical foundation for designing circumferential convergent hydrodynamic finger seals with high performance.