篦齿封严对核心机瞬态叶尖间隙仿真的影响

Influence of Labyrinth Seal on Transient Tip Clearance Simulation of Core Engine

中文关键词:  瞬态叶尖间隙  篦齿间隙  气热固双向耦合  核心机

英文关键词:transient tip clearance  seal clearance  aero-thermo-structural two-way coupling  core engine

中文摘要:

      针对核心机瞬态叶尖间隙仿真中存在多物理场耦合的问题，综合1维流体网络法、2维轴对称有限元法、温度与位移的 工程算法，在空气系统计算与轮盘机匣温度场计算间双向传递热流；使轮盘机匣温度场为位移计算提供材料物性的参考温度与热 载荷，位移计算反向提供气固换热面积；同时使位移计算为空气系统计算提供篦齿间隙值，建立基于气热固双向耦合的瞬态间隙 预估方法，并以核心机为模型，重点研究了篦齿间隙对叶尖间隙的影响。结果表明：在慢车状态下篦齿间隙对叶尖间隙的影响微 弱；而在起飞状态下，未耦合篦齿间隙将造成对应叶尖间隙值最大0.125 mm的计算误差，相对其间隙变化量达22.4%；但当篦齿间 隙变化量小于初值的44.9%，或目标叶尖间隙未与该篦齿所在空气系统支路相关时，上述影响将变得很小。对于起飞工况，当篦 齿间隙初值增大25%后，相应叶尖间隙变化量将增大15.7%。

英文摘要:

      In order to solve the problem of multiple physical fields coupling in the simulation of transient tip clearance about core engine, a 1D fluid network method, 2D axisymmetric finite element method, and the engineering calculation of temperature and displace? ment were integrated in this paper to enable bidirectional heat transfer between air system calculation and temperature field calculation of disc and casing; The temperature field of disc and casing provide a reference temperature of material properties and thermal load for displacement calculation, while displacement calculation provides the air-solid heat transfer area in reverse; At the same time, displace? ment calculation provides the seal clearance for air system calculation, finally, a transient clearance prediction method was established based on aero-thermo-structural two-way coupling, with a core engine as the model, the influence of the seal clearance on the tip clear? ance was emphatically studied. The results show that the seal clearance has a slight effect on tip clearance in idle state. In take-off state, without coupling seal clearance will cause the maximum calculation error of the corresponding tip clearance by 0.125mm, and it is up to 22.4% about the change of its tip clearance. However, when the seal clearance change is less than 44.9% of its initial value, or the target tip clearance is not related to the flow path where the seal is located, the above influence will be slight. When the initial seal clearance value increases by 25%, the corresponding tip clearance variation will increase by 15.7% in the take-off state.