Viscous oscillatory flow about a circular cylinder at small to moderate Strouhal number
Viscous oscillatory flow about a circular cylinder at small to moderate Strouhal number
复制标题
小到中等斯特劳哈尔数绕圆柱体的粘性振荡流
DOI：
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发表时间：
1995
影响因子：
3.7
通讯作者：
P. Nguyen
中科院分区：
文献类型：
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作者：
H. M. Badr;S. Dennis;S. Kocabiyik;P. Nguyen
考虑无限长圆柱体置于与圆柱体轴垂直方向振荡的无界粘性流体中所引起的瞬态流场，该流体处于静止状态。假定流从静止状态突然开始，并在运动方向上保持对称。求解方法基于对非定常Navier-Stokes方程进行精确数值积分的过程。对于中、高雷诺数的大时间值，已经进行了数值计算。研究了雷诺数和斯特罗哈尔数对层流对称尾流演化的影响，并与已有的数值和实验结果进行了比较。同时给出了阻力系数随时间的变化，并与无粘流解进行了比较。黏性流动和无黏性流动结果的比较表明，雷诺数和斯特劳哈尔数越高，结果越一致。计算了大时间的平均流量，发现与先前基于边界层理论的预测结果很好地吻合。
The transient flow field caused by an infinitely long circular cylinder placed in an unbounded viscous fluid oscillating in a direction normal to the cylinder axis, which is at rest, is considered. The flow is assumed to be started suddenly from rest and to remain symmetrical about the direction of motion. The method of solution is based on an accurate procedure for integrating the unsteady Navier–Stokes equations numerically. The numerical method has been carried out for large values of time for both moderate and high Reynolds numbers. The effects of the Reynolds number and of the Strouhal number on the laminar symmetric wake evolution are studied and compared with previous numerical and experimental results. The time variation of the drag coefficients is also presented and compared with an inviscid flow solution for the same problem. The comparison between viscous and inviscid flow results shows a better agreement for higher values of Reynolds and a Strouhal numbers. The mean flow for large times is calculated and is found to be in good agreement with previous predictions based on boundary-layer theory.