不同外罩型线短舱边界层的转捩位置预测  

Transition prediction of boundary layers over an engine nacelle with different outer covers

作　　者：文豪 苏彩虹 张美红 刘凯礼 王美黎 WEN Hao;SU Caihong;ZHANG Meihong;LIU Kaili;WANG Meili(Beijing Aerospace Technology Research Institute,Beijing 100074,China;School of Mechanical Engineering,Tianjin University,Tianjin 300072,China;Shanghai Aircraft Design and Research Institute,COMAC,Shanghai 201210,China;School of Aeronautics,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]北京空天技术研究所,北京100074 [2]天津大学机械工程学院,天津300072 [3]中国商用飞机有限责任公司上海飞机设计研究院,上海201210 [4]西北工业大学航空学院,西安710072

出　　处：《空气动力学学报》2024年第11期43-54,I0001,共13页Acta Aerodynamica Sinica

摘　　要：在设计短舱外罩型线时,希望尽可能使其表面边界层保持层流状态,以减小摩阻,提高有效载荷。理解边界层的转捩机制,并准确预估转捩发生的位置,有利于有效评估不同外罩型线设计方案。以巡航状态下3种不同外罩型线的通气短舱为研究对象,采用线性稳定性理论分析了边界层稳定性特征,并综合考虑T-S波和激波诱导分离泡这两种转捩机制,预测了不同外罩型线下短舱边界层的转捩位置。结果表明,逆压梯度越大,T-S波越不稳定,流动分离的位置也越靠前。因此,设计时应尽可能保持大范围的顺压梯度并减小逆压梯度,这将有利于推迟转捩发生。此外,针对风洞实验中的短舱缩比模型,比较了预测的转捩位置与实验转捩位置,发现两者的转捩线在形态上非常一致,进一步证实了预测方法的有效性。In the design of the nacelle outer cover profile,it is crucial to maintain the boundary layer's laminar state to minimize wall friction and enhance payload capacity.Understanding the boundary-layer transition mechanisms and accurately predicting the transition front is fundamental to effectively evaluate different designs of the nacelle.In this work,we focus on the stability characteristics of boundary layers over nacelle with three different outer covers under cruise conditions.Considering transition mechanisms correlated with the T-S waves and the shock wave-induced separation bubbles,the transition fronts are predicted.The results indicate that as the unfavorable pressure gradient increases,T-S waves become more unstable,leading to earlier boundary-layer separation.Therefore,maintaining a relatively large range of favourable pressure gradient as well as reducing unfavorable pressure gradient will delay the boundary-layer transition.In addition,for a scaled nacelle model,the predicted transition front and that obtained in wind tunnel tests are morphologically similar,confirming the validity of the prediction method.

关 键 词：转捩预测 短舱 边界层 线性稳定性理论 e^(N)方法 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]