Ground vortex aerodynamics under crosswind conditions
Ground vortex aerodynamics under crosswind conditions
复制标题
侧风条件下的地面涡空气动力学
DOI：
10.1007/s00348-010-0902-4
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发表时间：
2011
影响因子：
2.4
通讯作者：
D. MacManus
中科院分区：
文献类型：
--
作者：
J. Murphy;D. MacManus
进行了一项实验研究，利用立体粒子图像测速和管道内总压力测量来研究侧风条件下地面涡的形成。使用涡流强度和管道内畸变描述符来评估速度比、无量纲高度、接近边界层厚度和偏航角的影响。流场的特征是单个地面涡流，其强度随着速度比的减小而增加。涡流特性取决于离地间隙，在较低进气高度处观察到更强的涡流。对于高离地间隙，涡流强度在减小到零之前达到局部最大值，因为捕获流管不再与地平面相互作用。在低离地间隙时，涡流强度足以引起唇缘分离。接近的边界层厚度对涡特性没有显着影响。将进气偏航角从侧风减小到逆风配置会导致涡流强度单调减小，数据遵循 sin3(ψ) 关系，其中 ψ 是偏航角。畸变系数也与偏航角单调；然而，依赖性是sin6(ψ)。
An experimental study was performed to investigate ground vortex formation under crosswind conditions using stereoscopic particle image velocimetry and in-duct total pressure measurements. The effect of velocity ratio, non-dimensional height, approaching boundary layer thickness and yaw angle are assessed using vortex strength and in-duct distortion descriptors. The flow-field is characterized by a single ground vortex which increases in strength as the velocity ratio is reduced. The vortex characteristics depend on the ground clearance with a stronger vortex observed at lower intake heights. For a high ground clearance, the vortex strength reaches a local maximum before reducing towards zero as the capture streamtube no longer interacts with the ground plane. At a low ground clearance, the vortex strength is strong enough to induce a lip separation. The approaching boundary layer thickness has no notable influence on the vortex characteristics. Reducing the intake yaw angle from a crosswind to a headwind configuration leads to a monotonic decrease in vortex strength with the data following a sin3(ψ) relationship, where ψ is the yaw angle. The distortion coefficient was also monotonic with yaw angle; however, the dependence was sin6(ψ).