Three-dimensional numerical investigation of vortex-induced vibration of a rotating circular cylinder in uniform flow

2018 ◽  
Vol 30 (5) ◽  
pp. 053602 ◽  
Author(s):  
Adnan Munir ◽  
Ming Zhao ◽  
Helen Wu ◽  
Lin Lu ◽  
Dezhi Ning
Keyword(s):  
Circular Cylinder ◽  
Numerical Investigation ◽  
Three Dimensional ◽  
Uniform Flow ◽  
Vortex Induced Vibration ◽  
Rotating Circular Cylinder

Flow Simulation Around a Rotating Circular Cylinder With Surface Roughness by the Vortex Method

2003 ◽  
Author(s):  
Tetsuhiro Tsukiji ◽  
Yuko Matsubara
Keyword(s):  
Surface Roughness ◽  
Circular Cylinder ◽  
Flow Simulation ◽  
Vortex Method ◽  
Uniform Flow ◽  
Speed Ratio ◽  
Rotating Speed ◽  
Rotating Circular Cylinder ◽  
Two Dimensional Flow ◽  
Good Agreement

The two-dimensional flow around a rotating circular cylinder with surface roughness in a steady uniform flow is investigated using a vortex method. The Reynolds number is 9500, while the rotating speed ratios of the peripheral velocity to the uniform velocity is 0–1.0. The surface roughness is distributed around the circular cylinder and its strength is 0.5% of the diameter. The viscous diffusion effects and the no-slip condition are considered. Before the calculation for a rotating circular cylinder with the surface roughness, the flow simulation for a circular cylinder in the steady uniform flow was conducted to confirm the present method. The development of the twin vortices and the velocity profiles behind the circular cylinder at the beginning of the calculation are compared with the previous experimental results. It is found that the calculated results are in good agreement with the experiments. The development of the vortices, the drag and the lift coefficients are computed by changing the rotating speed ratio for the circular cylinder both with the surface roughness and without it. The influence of the surface roughness and the rotating speed ratio on the vortex development, the drag and the lift coefficients are examined.

Numerical investigation of wake flow regimes behind a high-speed rotating circular cylinder in steady flow

2019 ◽  
Vol 878 ◽  
pp. 875-906
Author(s):  
Adnan Munir ◽  
Ming Zhao ◽  
Helen Wu ◽  
Lin Lu
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Vortex Shedding ◽  
Rotation Rate ◽  
High Speed ◽  
Three Dimensional ◽  
Flow Regimes ◽  
Reynolds Numbers ◽  
Wake Flow ◽  
Rotating Circular Cylinder

Flow around a high-speed rotating circular cylinder for $Re\leqslant 500$ is investigated numerically. The Reynolds number is defined as $UD/\unicode[STIX]{x1D708}$ with $U$, $D$ and $\unicode[STIX]{x1D708}$ being the free-stream flow velocity, the diameter of the cylinder and the kinematic viscosity of the fluid, respectively. The aim of this study is to investigate the effect of a high rotation rate on the wake flow for a range of Reynolds numbers. Simulations are performed for Reynolds numbers of 100, 150, 200, 250 and 500 and a wide range of rotation rates from 1.6 to 6 with an increment of 0.2. Rotation rate is the ratio of the rotational speed of the cylinder surface to the incoming fluid velocity. A systematic study is performed to investigate the effect of rotation rate on the flow transition to different flow regimes. It is found that there is a transition from a two-dimensional vortex shedding mode to no vortex shedding mode when the rotation rate is increased beyond a critical value for Reynolds numbers between 100 and 200. Further increase in rotation rate results in a transition to three-dimensional flow which is characterized by the presence of finger-shaped (FV) vortices that elongate in the wake of the cylinder and very weak ring-shaped vortices (RV) that wrap the surface of the cylinder. The no vortex shedding mode is not observed at Reynolds numbers greater than or equal to 250 since the flow remains three-dimensional. As the rotation rate is increased further, the occurrence frequency and size of the ring-shaped vortices increases and the flow is dominated by RVs. The RVs become bigger in size and the flow becomes chaotic with increasing rotation rate. A detailed analysis of the flow structures shows that the vortices always exist in pairs and the strength of separated shear layers increases with the increase of rotation rate. A map of flow regimes on a plane of Reynolds number and rotation rate is presented.

Sign in / Sign up

Export Citation Format

Share Document