INITIAL FLOW PAST AN IMPULSIVELY STARTED CIRCULAR CYLINDER
INITIAL FLOW PAST AN IMPULSIVELY STARTED CIRCULAR CYLINDER
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DOI：
10.1093/qjmam/26.1.53
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发表时间：
1973-01-01
影响因子：
0.9
通讯作者：
DENNIS, SCR
中科院分区：
文献类型：
--
作者：
COLLINS, WM;DENNIS, SCR
考虑了粘性流体中沿无限大圆柱体垂直方向以匀速冲击启动的初始流动。通过考虑有限雷诺数的修正，得到了从运动开始到时间的幂展开式，推广了边界层理论的结果。从而可以得到有限雷诺数时流动的早期物理性质的发展情况。特别是，流体第一次开始从圆柱体分离的时间的合理近似可以计算为约r=200，其中R是基于圆柱体直径的雷诺数。如果RI值足够大，则扩展在首次分离时间之后的时间内有效。给出了气缸阻力随时间的初始发展结果。在运动开始时，所有雷诺数的摩擦阻力和压力阻力都是相等的。
The initial flow in a direction normal to an infinite circular cylinder which is started impulsively from rest with uniform velocity in a viscous fluid is considered. An expansion in powers of the time from the start of the motion is obtained which extends the results of boundary-layer theory by taking into account corrections for finite Reynolds numbers. The odevelopment of the physical properties of the flow at early times for finite Reynolds numbers may thus be obtained. In particular, a reasonably good approximation to the time at which the fluid first starts to separate from the cylinder can be calculated down to aboutR= 200, where R is the Reynolds number based on the diameter of the cylinder. The expansion is valid for times beyond the time at which separation first occurs, ifRis large enough. Results are presented for the initial development with time of the drag on the cylinder. At the start of the motion the friction and pressure drags are equal for all Reynolds numbers.