机动载荷对核心机叶尖间隙的影响初探

以典型航空发动机核心机为对象,研究模型简化方法,建立完整的计算模型,通过分析机动飞行过程中的主要载荷及作用方式,通过有限元数值模拟,得到机动载荷作用下叶尖径向间隙的变化规律,为研究间隙变化对发动机性能影响提供参考依据。分析发现:陀螺力矩和法向过载均使核心机产生明显的变形,陀螺力矩导致叶尖径向间隙相对变化量的平均值达-2.174,法向过载对叶尖径向间隙变化影响相对较弱,相对变化量的平均值达到-1.572。因此在研究叶尖径向间隙时,不能忽略机动载荷的作用效果。 

Initial research on impacts of maneuver loadson core engine tip clearance

Based on a typical aircraft engine, the calculation model was built by studying model simplification methods and analyzing main loads and loading procedures in maneuver flight. By grasping the change rule of radial tip clearance subjected to different kinds of maneuvering loads by finite element simulation, it can provide significant reference for studying the effects of tip clearance variation on aero-engine performance. Discovered by rational analysis on the distortion of cases and rotors in consequence of gyroscopic moment and normal overload, it can be concluded that two kinds of loads can cause distinct deformation in the core engine. The mean of the relative variation of radial tip clearance subjected to gyro moment was up to -2.174, while the value subjected to normal overload was up to -1.572 owing to the weaker influence of normal overload. Consequently, the impacts of maneuvering loads on engines cannot be ignored when studying the radial tip clearance variation.