Near-Surface Topology and Flow Structure on a Delta Wing with Low Sweep Angle
Near-Surface Topology and Flow Structure on a Delta Wing with Low Sweep Angle
复制标题
小后掠角三角翼的近地表拓扑和流动结构
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
D. Rockwell
中科院分区：
文献类型：
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作者：
M. Elkhoury;M. Yavuz;D. Rockwell
流线，以及相应的速度和涡量模式，是利用基于激光的高图像密度粒子图像测速技术，在与三角翼表面直接相邻的平面上表征的。该技术提供了近表面流线拓扑的瞬时状态序列，以及相应的时间平均状态，以及相关的临界点。这些拓扑特征是根据平均和非定常速度和平均涡量的模式来解释的，这些模式允许识别沿机翼表面的非定常区域。这些固定翼上的流型表示也适用于俯仰模式下机翼受到小幅度扰动的情况。当扰动达到或接近定翼上主要非定常事件固有频率时，会导致表面拓扑结构和流动结构发生实质性变化。此外，这种拓扑结构和流动结构对瞬态斜向俯仰运动的响应被处理，以定义在机翼运动停止后立即放松过程中的状态继承。
The streamlines, and the corresponding patterns of velocity and vorticity, are characterized on a plane immediately adjacent to the surface of a delta wing using a laser-based technique of high-image-density particle image velocimetry. This technique provides the sequence of instantaneous states, as well as the corresponding time-averaged state, of the near-surface streamline topology and the associated critical points. These topological features are interpreted in terms of patterns of averaged and unsteady velocity, and averaged vorticity, which allow identification of regions of unsteadiness along the surface of the wing. These representations of the flow patterns on the stationary wing are also employed for the case of the wing subjected to small-amplitude perturbations in the pitching mode. Perturbations at or near the inherent frequency of the predominant unsteady event on the stationary wing yield substantial changes of the surface topology and flow structure. Furthermore, response of this topology and flow structure to transient, ramplike pitching motion is addressed to define the succession of states during the relaxation process immediately after cessation of the wing motion.