Quantitative characteristics of a laminar, unsteady necklace vortex system at a rectangular block-flat plate juncture
Quantitative characteristics of a laminar, unsteady necklace vortex system at a rectangular block-flat plate juncture
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DOI：
10.1017/s002211209500067x
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发表时间：
1995-03
影响因子：
3.7
通讯作者：
C. V. Seal;C. Smith;O. Akin;D. Rockwell
中科院分区：
文献类型：
--
作者：
C. V. Seal;C. Smith;O. Akin;D. Rockwell
采用氢气泡流动显示和粒子图像测速技术（PIV）对矩形海崖体与平板交界处形成的非定常层流项链涡系进行了实验研究。涡流系统被发现表现出不稳定的行为类似于其他研究人员所描述的圆柱体平板交界处，其特征在于周期性形成的项链涡上游的身体，随后脱离和平流对块。对对称平面上的PIV测量结果的详细分析表明，涡系中涡量平衡的主要机制是项链涡涡量与物体接近表面相互作用产生的相反符号的涡量的交叉抵消。
The unsteady laminar necklace vortex system formed at the junction of a rectangular bluff body and a flat plate was studied experimentally using hydrogen bubble flow visualization and particle image velocimetry (PIV). The vortex system was found to exhibit unsteady behaviour similar to that described by other investigators for cylinder-flat plate junctures, and is characterized by the periodic formation of necklace vortices upstream of the body that subsequently break away and advect towards the block. Detailed analysis of PIV measurements on the plane of symmetry indicates that the dominant mechanism for vorticity balance in the vortex system is the cross-cancellation of the vorticity of the necklace vortex with vorticity of opposite sign generated by interaction of the necklace vortex with the approach surface to the body.