论文标题
在亚临界雷诺数处弹性安装的狭缝缸的流动特性
Flow Characteristics of Elastically Mounted Slit Cylinder at Sub-critical Reynolds Number
论文作者
论文摘要
本工作通过数值研究了二维圆柱体的涡流振动（VIV），其轴对称缝隙在Reynolds编号为500。振动响应和相关的流动特性。结果表明，缝隙的添加通过向主流量增加额外的流量来有助于VIV抑制。它导致稳定的唤醒，并在圆柱体下游的压力回收中恢复，并导致圆柱体上的升力减少。同样，存在与不同缝隙形状相关的不同脱落模式。流场的正确正交分解（POD）表明，在所有三个缝隙中，与其他缝隙（收敛的缝隙和不同的缝隙）相比，平行的狭缝通过将能量量分配到大量模式（大部分能量）中，通过将能量量分配到大量模式中，从而在圆柱体后面进行了重大修饰。此外，增加相对于自由式的狭缝角（对于平行狭缝）将缝隙有效性提高到狭缝 - 角度的特定值，而之外开始会对VIV抑制产生不利影响。还从抑制VIV的角度报告了对狭缝宽度影响的观察结果。
The present work numerically investigates vortex-induced vibrations (VIV) of a two-dimensional circular cylinder with an axisymmetric slit at Reynolds number 500. The study examines the effects of slit shape (i.e., converging, diverging, and parallel slits), the effect of slit-area ratios, slit-width, and its angle with the freestream velocity on aerodynamic forces, vibration response, and associated flow characteristics. The results demonstrate that the addition of the slit assists the VIV suppression by adding an extra amount of flow to the main flow. It results in the stabilized wake with the pressure recovery downstream of the cylinder and causes a reduction in the lift force over the cylinder. Also, there exist different shedding patterns associated with different slit shapes. Proper Orthogonal Decomposition (POD) of the flow field suggests that among all the three slits, the parallel slit heavily modifies the flow behind the cylinder by distributing the amount of energy to a large number of modes as compared to other slits (converging slit and diverging slit), where the most of the energy is contained in a couple of modes. Further, increasing the slit angle (for parallel slit) with respect to the freestream increases the slit effectiveness up to a specific value of slit-angle and beyond that starts to affect the VIV suppression adversely. Observations for the effect of slit-width are also reported from the perspective of suppression of VIV.
