Unsteady pressure field and vorticity production over a pitching airfoil
Unsteady pressure field and vorticity production over a pitching airfoil
复制标题
俯仰翼型上的非定常压力场和涡度产生
DOI：
10.2514/3.10931
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发表时间：
1992
期刊：
影响因子：
2.5
通讯作者：
Metwally H. Metwally
中科院分区：
文献类型：
--
作者：
Mukund Acharya;Metwally H. Metwally
在一个二维NACA 0012翼型模型进行单次上仰运动时，在一定的无量纲俯仰速率范围内测量了非定常压力场和来自表面的展向涡量通量的变化。研究结果表明，在动态失速涡的产生、发展、增长和运动中起关键作用的机理。翼型上的非定常压力分布受三个特征支配，它们的出现和发展被用来区分两类行为，对应于低和高俯仰速率。此外，还发现来自表面的涡量通量主要来自五个集中区域或源，其中大部分位于翼型表面的前部。来自这些源的涡量通量的行为与负责流场发展的相互作用机制有关。描述了这些特征在压力和表面涡量通量变化中随俯仰角速度的变化。
The unsteady pressure field and the accompanying variations in the flux of spanwise vorticity from the surface were measured over a range of dimensionless pitch rates for a two-dimensional NACA 0012 airfoil model undergoing a single pitch-up motion. The results were examined to identify the mechanisms that play key roles in the initiation, development, growth, and movement of the dynamic-stall vortex. The unsteady pressure distribution over the airfoil was dominated by three features, whose emergence and evolution were used to distinguish between two classes of behavior, corresponding to low and high pitch rates. Further, it was found that the flux of vorticity from the surface originated primarily from five concentrated regions or sources, the majority of which were located over the forward portion of the airfoil surface. The behavior of vorticity flux from these sources was related to the interacting mechanisms responsible for the development of the flowfield. The change of these features in the pressure and surface vorticity flux variations with the pitch rate is described.