摘要
航空发动机吸入冰晶会导致推力损失甚至叶片损坏,对飞行安全构成潜在威胁。为了研究冰晶在压气机叶栅中的撞击特性,建立了一种分别计算颗粒撞击叶片压力面和吸力面时运动轨迹的方法,该方法可以避免冰晶颗粒轨迹交叉。在此基础上,对颗粒等效直径和形状对冰晶撞击特性的影响进行了数值模拟研究。结果表明,总收集系数随颗粒等效直径和长宽比的增加而增加。对于相同形状的颗粒,当颗粒直径从20μm增加到50μm时,总收集系数增加了44.1%;对于相同等效直径的颗粒,当颗粒长宽比从0.1增加到10时,总收集系数增加了39%。叶片压力面收集系数的增加是总收集系数增加的主要原因。冰晶撞击叶片前缘时发生破碎现象,撞击叶片表面时发生反弹现象。在叶片表面的大部分区域,冰晶颗粒发生非弹性反弹。就粒径而言,二次撞击后收集系数的分布趋势与一次撞击近似,二次收集系数的最大值减少了约70%。然而,就颗粒长宽比而言,叶片前缘处二次撞击收集系数的分布趋势与一次撞击相反,细长型冰晶颗粒撞击叶片前缘的二次收集系数反而低于粗短型冰晶颗粒撞击叶片前缘的二次收集系数。
Ingestion of the ice crystals in aircraft engines can lead to the thrust loss or even blade damage,posing a potential threat to flight safety.To investigate the impact characteristics of the ice crystals in the compressor cascade,a method is established to calculate the trajectories of ice crystal particles impacting the blade pressure surface and suction surface separately which can avoid the intersections of the particle trajectories.Based on this method,the effect of the particle size and shape on the ice crystal impact characteristics are numerically studied in details.Results show that the total collection coefficient increases with the increase of the particle equivalent diameter and aspect ratio.For the particles with the same shape,the total collection coefficient increases by 44.1%when the particle diameter increases from 20μm to 50μm;for the particles with the same size,the total collection coefficient increases by 39%when the particle aspect ratio increases from 0.1 to 10.The increase of the collection coefficient of the blade pressure surface is the main reason for the increase of the total collection coefficient.The blade leading edge is mainly characterized by the fragmentation of ice crystals and the blade surface is mainly characterized by the rebound of the ice crystals.In most parts of the blade surface,the ice crystal particles have a non-elastic rebound.In terms of the particle size,the distribution trend of the collection coefficient after the secondary impact is very similar to that of the primary impact,with a notable difference being a reduction of about 70%of the maximum value of the collection coefficient.However,in terms of the particle aspect ratio,the trend of the secondary impact collection coefficient at the leading edge of the blade is opposite to that of the primary impact,with elongated ice crystal particles exhibiting a lower secondary collection coefficient.
作者
贾惟
顾元昊
JIA Wei;GU Yuanhao(College of Safety Science and Engineering,Civil Aviation University of China,Tianjin 300300,P.R.China;Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,P.R.China)
基金
supported by the Fundamental Research Funds for the Central Universities(No3122025101).
关键词
冰晶
压气机叶栅
收集系数
一次撞击
二次撞击
ice crystal
compressor cascade
collection coefficient
primary impact
secondary impact
