Effects of an axial flow component on the Honji instability |
| |
Institution: | 1. CORIA-UMR 6614 - Normandie Université CNRS-Université et INSA Rouen-Normandie, Rouen 76000, France;2. LHEEA Laboratory, Ecole Centrale de Nantes (CNRS UMR 6598), Nantes 44300, France |
| |
Abstract: | This paper is concerned with a numerical study of the three-dimensional Honji instability that can arise in an oscillatory flow impinging on a circular cylinder. It is well known that when the fluid motion far from the cylinder is perpendicular to its axis then the flow is liable to a three-dimensional breakdown via this instability which initially appears as an axially periodic mushroom-like structure attached to the surface of the cylinder. Here the focus is on examining the Honji instability under an oblique inflow. The obliqueness of the free stream is represented by an angle of attack through introducing an axial flow component. It is found that the Honji mode is suppressed by increasing the axial flow component, and when this component is sufficiently large the instability mechanism is no longer operative so that all that remains is a featureless two-dimensional columnar flow. At smaller values of angle of attack, though the Honji structure remains, it is deformed by the axial flow component. The developed two-layer near-cylinder vortical structures can be related to the energy and momentum transfer between the two layers. |
| |
Keywords: | Oscillatory flow Honji instability Numerical methods Angle of attack |
本文献已被 ScienceDirect 等数据库收录! |
|