微型摆式内燃机蜂窝密封设计及流场分析

Honeycomb seal design and flow field analysis for miniature pendulum internal combustion engine

微型摆式内燃机结构缩小后,泄漏明显增加,热效率显著下降。为改善其径向泄漏问题,提出了一种新型蜂窝密封结构,实现蜂窝与中心摆一体化设计,避免了传统蜂窝密封结构与基体分离安装的复杂性。利用数值方法比较蜂窝密封和光滑间隙密封对质量泄漏的影响规律,从而验证蜂窝密封设计的有效性。应用FLUENT软件分析微型摆式内燃机蜂窝参数变化对密封流场特性的影响,研究结果表明,当蜂窝壁厚小于0.2 mm或对边距小于1.2 mm时,随着结构参数增加,有利于蜂窝密封的封严特性实施;相反,蜂窝结构参数变化对密封流场压力的影响较小。

After the structure of miniature pendulum internal combustion engine is reduced,the leakage increases significantly and the thermal efficiency decreases significantly.To improve its radial leakage problem,a new honeycomb seal structure is proposed to realize the integrated design of honeycomb and center pendulum,which avoids the complexity of installing the traditional honeycomb seal structure separately from the substrate.Numerical methods are used to compare the influence law of honeycomb seal and smooth gap seal on mass leakage,so as to verify the effectiveness of the honeycomb seal design.The FLUENT software is applied to analyze the effect of honeycomb parameter variation on the sealing flow field characteristics of the miniature pendulum internal combustion engine.The research results show that when the honeycomb wall thickness is less than 0.2 mm or the opposite edge distance is less than 1.2 mm,the implementation of the sealing characteristics of the honeycomb seal is facilitated as the structural parameters increase;on the contrary,the effect of honeycomb structural parameter variation on the sealing flow field pressure is smaller.