Interaction of turbulence with the leading-edge stagnation point of a thin aerofoil
Interaction of turbulence with the leading-edge stagnation point of a thin aerofoil
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DOI：
10.1017/jfm.2016.326
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发表时间：
2016-06
影响因子：
3.7
通讯作者：
Lorna J. Ayton;N. Peake
中科院分区：
文献类型：
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作者：
Lorna J. Ayton;N. Peake
本文建立了一个渐近模型，分析了均匀流中远上游产生的湍流与椭圆形固体的相互作用。前缘驻点引起入射涡量的显著变形，因此我们的分析集中在与头部半径接近驻点的尺寸缩放区域。快速畸变理论用于将单个非定常阵风扰动产生的流场分离为对流非声学部分和声学部分，对流非声学部分包含上游涡扰动的演化，声学部分由涡量与固体表面的相互作用产生，这在阵风-翼型相互作用理论中是典型的。使用单频阵风响应解，沿着与冯卡门能谱，我们发现的湍流压力谱均匀各向同性湍流入射从遥远的上游。高频和低频阵风都被认为是允许近似的湍流压力谱接近前缘，远离身体接近入射滞止流线。近场和远场前缘湍流压力谱的渐近结果与最近的实验结果之间显示出良好的一致性。
An asymptotic model is constructed to analyse the interaction of turbulence generated far upstream with a thin elliptic-nosed solid body in uniform flow. The leading-edge stagnation point causes significant deformation of incident vorticity, and hence our analysis focuses on the region of size scaling with the nose radius close to the stagnation point. Rapid distortion theory is used to separate the flow field generated by a single unsteady gust perturbation into a convective non-acoustic part, containing the evolution of the upstream vortical disturbance, and an acoustic part generated by the interaction of the vorticity with the solid surface, as is typical in gust–aerofoil interaction theory. Using single-frequency gust response solutions, along with a von Kármán energy spectrum, we find the turbulent pressure spectrum generated by homogeneous isotropic turbulence incident from far upstream. Both high- and low-frequency gusts are considered to allow approximations to be found for the turbulent pressure spectra close to the leading edge, and far from the body close to the incident stagnation streamline. Good agreement is shown between the asymptotic results for the near- and far-field leading-edge turbulent pressure spectra and recent experimental findings.