CAJ | 학술논문

采用大涡模拟方法，研究斜置圆柱在展向剪切流作用下的气动性能。研究了不同剪切流强度对斜置圆柱的表面风压、Strouhal 数、气动力时程及其功率谱、气动力展向相关性等气动性能的影响，并探讨了剪切流对斜圆柱气动性能的作用机理。结果表明：在均匀流作用下，斜置圆柱尾流区会产生强烈的轴向流，卡门涡脱强度大大减弱；展向剪切流对斜置圆柱的表面风压和气动力等气动性能有较大影响；展向剪切流会破坏轴向流在斜置圆柱尾流区的形成，并且当剪切流的剪切系数足够大时，可完全阻止轴向流的出现，从而减弱或消除了抑制卡门涡脱的因素，恢复了斜置圆柱的卡门涡脱强度。
채용대와모의방법，연구사치원주재전향전절류작용하적기동성능。연구료불동전절류강도대사치원주적표면풍압、Strouhal 수、기동력시정급기공솔보、기동력전향상관성등기동성능적영향，병탐토료전절류대사원주기동성능적작용궤리。결과표명：재균균류작용하，사치원주미류구회산생강렬적축향류，잡문와탈강도대대감약；전향전절류대사치원주적표면풍압화기동력등기동성능유교대영향；전향전절류회파배축향류재사치원주미류구적형성，병차당전절류적전절계수족구대시，가완전조지축향류적출현，종이감약혹소제료억제잡문와탈적인소，회복료사치원주적잡문와탈강도。
Aerodynamic characteristics of an inclined circular cylinder in a span-wise shear flow were investigated using the large eddy simulation (LES).The effects of different shear flow intensities on surface pressure distributions, Strouhal number,time history and power spectral density (PSD)of aerodynamic forces,and span-wise correlation of wind forces of the inclined cylinder were discussed.Furthermore,the possible influence mechanism of the shear flow on the cylinder was studied.It was shown that under the condition of a uniform incoming flow,a strong axial flow appears behind the inclined cylinder and Karman vortex shedding caused by the axial flow is largely weakened;however,when the incoming flow involves span-wise linear non-uniformity,the intensity of the axial flow decreases and even disappears if the intensity of the shear flow is high enough;furthermore,the shear flow causes the recovery of the intense Karman vortex behind the inclined cylinder and has substantial effects on the aerodynamic characteristics of the cylinder.