Influence of near-leading edge curvature on the performance of aero-engine intake lips at high-incidence
Influence of near-leading edge curvature on the performance of aero-engine intake lips at high-incidence
复制标题
近前缘曲率对航空发动机进气唇高迎角性能的影响
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
E. Platt
中科院分区：
文献类型：
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作者：
A. Coschignano;H. Babinsky;C. Sheaf;E. Platt
本文研究了亚音速发动机进气道唇口有攻角的绕流，着重研究了内唇口激波与边界层的干扰。基线几何形状被视为沿着有两种变化，其特征在于更尖锐和更钝的进气道突出部分（即：机舱前缘）。到目前为止的结果表明，基线模型的相互作用是比较良性的，在符合典型起飞或爬升条件的设计条件下，激波诱导分离很小或没有激波诱导分离。替代的几何形状揭示了相当大的影响，近高光曲率的流动发展。特别是，钝头会导致形成更大的超音速区，并以更强的激波终止，从而表现出更大程度的激波诱导分离和增加的总压损失和不稳定性。另一方面，尖锐的鼻子导致通过三个单独的冲击波发生压缩，所有这些冲击波都很弱。总的来说，三种进气几何形状都没有表现出固有的不稳定特性。然而，随着发动机流量需求的增加，预计会发生这种情况。进一步的测试正在进行中，以评估非设计性能，并产生一个完整的运行包线的进水口在发病率。
This paper describes the investigation into the flow over the lip of subsonic engine intakes at incidence, focusing on the shock wave-boundary layer interaction occurring over the inner lip. A baseline geometry is considered along with two variations, characterised by a sharper and a blunter intake highlight (i.e.: nacelle leading edge) respectively. Results to date reveal a relatively benign interaction for the baseline model, with small or no shock- induced separation reported under on-design conditions, which correspond to typical take- off or climb circumstances. The alternative geometries reveal a considerable influence of near-highlight curvature on the flow development. In particular, a blunter nose leads to the formation of a larger supersonic region, terminated by a consequently stronger shock, which shows a greater degree of shock-induced separation and increased total pressure losses and unsteadiness. The sharp nose, on the other hand, resulted in the compression occurring via three separate shock-waves, all of which weak. Overall, none of the three intake geometries showed inherently unsteady behaviour. However, this is expected to occur as the engine flow demand increases. Further testing is in progress to assess off-design performance and to produce a complete operational envelope for intakes at incidence.