跨音速风扇转子冰撞击损伤规律及抗冰 撞击改进设计研究

Law of Ice Impact Damage of Rotor in Transonic Fan and Improvement Design of Anti-ice Impact

目的揭示脱落冰形状、运动轨迹和姿态对航空发动机风扇转子叶片的撞击损伤规律,增强叶片的抗冰撞击能力。方法采用LS-DYNA进行数值模拟,开展脱落冰与叶片的撞击过程和叶型改进设计研究。结果叶片的撞击损伤程度受脱落冰结构强度的影响,在同样的撞击条件下,叶片受球体冰撞击损伤最严重,而受片体冰撞击损伤最轻。叶片的损伤程度由叶片和脱落冰之间的相对速度和叶片切割冰块的质量共同决定,叶片切割脱落冰的质量越大,塑性变形越严重。当脱落冰入射角为45°时,叶片损伤最严重,对叶片的最大撞击力为17828 N,最大内能达到126 J;当冰片从原始姿态绕y轴旋转90°时,对叶片前缘的撞击载荷最大,叶片塑性变形最严重。改进后,叶片受沿45°入射角脱落冰撞击后最大内能减小16%,失速裕度提高16.2%,峰值效率提高0.33%。结论跨音速风扇转子撞击损伤位置在前缘附近,增大叶片进口几何角和局部厚度能显著提高叶片抗冰撞击能力。

The work aims to reveal the impact damage law of aeroengine fan rotor blades caused by the shape,trajectory and attitude of falling ice and enhance the ability of blades to resist ice impact.LS-DYNA was used to conduct numerical simulation to investigate the impact process between falling ice and blades,and the improvement design of blades.The extent of impact damage to the blades was affected by the structural strength of falling ice.Under the same impact conditions,the spherical ice caused the most damage to the blades whereas the flake sustains the least amount of impact damage.The damage degree of blades was determined by both the relative velocity between the blades and the falling ice and the mass of the ice cut by blades.The plastic deformation degree of blades increased with the mass of falling ice cut by blades.The blades suffered the most severe damage when the incidence angle of falling ice was 45°,with the maximum impact force of 17828 N and the maximum internal energy of 126 J.The leading edge of blade experienced the greatest impact load and the most serious plastic deformation when the ice flake rotated 90°around the y-axis from its initial attitude.After the improvement,when the blades were impacted by the falling ice at the incident angle of 45°,the maximum internal energy of the blades decreased by 16%,the stall margin increased by 16.2%,and the peak efficiency increased by 0.33%.The impact damage position of transonic fan rotor is near the leading edge and increasing the inlet geometric angle and local thickness of the blades can significantly enhance the ability to resist ice impact.