摘要
为了寻找一种减阻、减振而又不受流动方向限制的方法,提出了一种可降低绕流阻力的波状圆柱,并对波状圆柱的平均阻力系数以及表面压力分布进行了实验研究.实验在某低速风洞进行,工作段的横截面尺寸为0.6 m×0.6 m,湍流度小于0.2%.实验中的Re在2.0×104到5.0×104范围内.实验结果表明:3种不同倾斜度的波状圆柱平均阻力系数小于普通圆柱的平均阻力系数,最大减阻效果可达20%以上;流体在波状圆柱的最小横截面上分离得早,表面压力下降快;波状圆柱表面倾斜度是影响流场的重要参数,其取值大小直接影响波状圆柱的减阻效果.
The effects of different degrees of obliqueness of wavy cylinders on drag reduction on cylindrical structures were experimentally investigated. The experiments were carried out in a low speed wind tunnel with a cross-section of 0.6 m× 0. 6 m and a free-stream turbulent intensity of less than 0.2%. The Reynolds numbers, based on the free-stream velocity and the nominal cylinder diameter, vary from about 2.0 × 10^4 to 5.0 × 10^4. Measurements on mean drag force induced by a cross flow over three wavy cylinders and the circumferential pressure distributions at various spanwise positions were conducted. The results show that the mean drag coefficients of the wavy cylinders are less than that of a corresponding circular cylinder ; a drag reduction of up to 20% was obtained. Furthermore, the pressure distribution indicates that the pressure drop is more rapid and the separation is earlier at the geometric saddle than those at other spanwise locations for wavy cylinders. These effects become more evident as the degree of obliqueness increases.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2006年第1期93-96,124,共5页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(5050602250275117)
教育部留学回国人员科研启动基金资助项目
关键词
波状圆柱
分离流
减阻
wavy cylinder
separated flow
drag reduction
