CAJ | 학술논문

该文基于k - ε湍流模型,采用Galerkin有限元法对并列旋转双圆柱的绕流特性进行了数值模拟,计算的雷诺数为 1550.为了考查两圆柱旋转和间距的相互作用,文中采用三种间距比分别是T/D = 1.2,1.6和3.0 (T 为两圆柱中心之间的距离,D为圆柱直径) 和一系列不同的旋转速度比 (|α| ≤ 2).计算显示,当 |α| = 0,即圆柱不转动时,对应三种间距有三种典型的流型,单钝体流型对应小间距、偏流对应中等间距和对称流对应大间距;当 |α| 达到临界值时,涡脱落得到了有效的抑制,流动趋于稳定,升力系数和阻力系数的脉动值趋于零;平均升力系数和阻力系数随着 |α| 的增大分别增大和减小.
해문기우k - ε단류모형,채용Galerkin유한원법대병렬선전쌍원주적요류특성진행료수치모의,계산적뢰낙수위 1550.위료고사량원주선전화간거적상호작용,문중채용삼충간거비분별시T/D = 1.2,1.6화3.0 (T 위량원주중심지간적거리,D위원주직경) 화일계렬불동적선전속도비 (|α| ≤ 2).계산현시,당 |α| = 0,즉원주불전동시,대응삼충간거유삼충전형적류형,단둔체류형대응소간거、편류대응중등간거화대칭류대응대간거;당 |α| 체도림계치시,와탈락득도료유효적억제,류동추우은정,승력계수화조력계수적맥동치추우령;평균승력계수화조력계수수착 |α| 적증대분별증대화감소.
Flow around two rotating side-by-side circular cylinders in a cross flow was numerically simulated using Galerkin finite element method based on k - ε turbulent model. In order to investigate the combined effects of the rotating and the spacing between two circular cylinders, the numerical simulations were performed at a various range of absolute rotating speeds (|α| ≤ 2) for three spacing ratios T/D = 1.2, 1.6 and 3.0 (T is the transverse distance between the centers of two circular cylinders, D is the diameter of the circular cylinders.) at Reynolds number of 1550. In the case of |α| = 0, three classic flow patterns are obtained: single bluff-body vortex shedding at small T/D, biased flow at intermediate T/D and synchronized vortex shedding at larger T/D. As |α| being beyond the critical rotational speed, vortex shedding was completely suppressed, the flow becomes steady and the fluctuation of lift and drag coefficients tend to zero. The mean values of lift and drag coefficients increase and decrease respectively with increasing |α|.