CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

no karman vortex street occur in the simulation of the flow over a cylinder

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 8, 2021, 04:49
Default no karman vortex street occur in the simulation of the flow over a cylinder
  #1
New Member
 
Join Date: Nov 2021
Location: China
Posts: 1
Rep Power: 0
TyuYooh is on a distinguished road
Hello,
I have trouble making a simulation of the flow over a circle cylinder.
Fig.1 is the 2D case I did before, and Karman vortex street appeared obviously.

But when I try to do a 3D case, the wake becomes straight and no periodic vortex shedding (Fig.2-Fig.5)

Parameters of the case:
·Diameter=0.01m
·Height=0.03m
·Velocity of the incoming flow=0.01m/s
·Reynolds number=100 (laminar flow)

The fluid region:
·X Direction(incoming flow): -7.5D/+25D from the axis of the cylinder
·Y Direction: ±10D from the axis
·Z Direction: 1D from the top/bottom face of the cylinder

Boundaries:
·Faces of the cylinder: walls
·Inlet/ outlet: velocity inlet/ pressure outlet
·Top & bottom faces(along the Z axis): symmetry
·Side faces(along the Y axis): walls

Physics:
·3D
·Segregated Flow
·Laminar
·Constant Density
·Gradients
·liquid(water, μ=1.002e-3Pa·s, ρ=998kg/m³
·Implicit Unsteady

I have refined the mesh from 800 thousand to 5 million, so it is unlikely to be a problem of grid.
In fact, I had also try to simulate the turbulance case using k-ε and k-omega SST(u=0.394m/s, Re=3900), but the flow field looks similar to the laminar one (Fig.2-Fig.5)
Does anyone have an idea? Please help me.
Attached Images
File Type: png 2d.png (62.0 KB, 18 views)
File Type: jpg 10s.jpg (197.6 KB, 21 views)
File Type: jpg 20s.jpg (196.9 KB, 15 views)
File Type: jpg 30s.jpg (193.1 KB, 14 views)
File Type: jpg 40s.jpg (187.4 KB, 12 views)
TyuYooh is offline   Reply With Quote

Reply

Tags
flow over a cylinder, karman vortex street, three dimensions

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to approach CFD simulation results of the flow past a cylinder? Ashkan Kashani Main CFD Forum 3 February 7, 2022 02:46
Issues on the simulation of high-speed compressible flow within turbomachinery dowlee OpenFOAM Running, Solving & CFD 11 August 6, 2021 06:40
First ever simulation of the Karman Street behind a Circular Cylinder? When? Who? rmittal Main CFD Forum 0 October 18, 2016 14:17
Von Karman street simulation with icoFoam agrewal OpenFOAM Running, Solving & CFD 3 February 9, 2008 17:12
Karman vortex street Zhipeng FLUENT 5 June 24, 2002 11:00


All times are GMT -4. The time now is 23:53.