CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Surface Pressure Osciallation

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 28, 2009, 10:40
Default Surface Pressure Osciallation
  #1
New Member
 
Matt
Join Date: Sep 2009
Posts: 12
Rep Power: 16
kawamatt2 is on a distinguished road
I am simulating flow around a wind turbine blade section. The Reynolds number is quite high (3e6) and as such i am using a turbulent model. I am none too familiar with turbulence theories but have been using the k-omega with a turbulent kinetic energy calculated via k=(3/2)(Ti*U)^2 and specific dissipation from k/w<=Re .

I am searching for a steady state solution to compare with some experimental results. The simulation runs and converges fine and lift data is roughly 5% low compared to the experimental data. Where i'm having issues is on the surface pressure distributions. I'm getting some checker boarding on the top leading edge of the airfoil and i can't figure out why. Below is an element plot of the pressure contour and i have circle the checker boarding.



Here is a picture of my grid. I built the grid in such a way that for the first 1% of chord away from the airfoil i used a structured grid and then progressed to an unstructured grid. Also a closeup of the mesh near the airfoil. I am using a Y+ of about 14 here. I have tried from 20 down to 4 with the same oscillating surface pressure results.




Here is a plot of the surface pressure compared to the experimental data i have. You can see the squigles at the top leading edge of the airfoil.



Anyone have any ideas on how to get rid of these. I have read about the Rhie and Chow technique of discretization and i and assume fluent can use this. I must be using the wrong solver or have a parameter set wrong. Also this is an incompressible simulation.
kawamatt2 is offline   Reply With Quote

Reply

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
"Pressure Inlet" Boundary Setup Wijaya FLUENT 15 May 18, 2016 10:08
Calculation of the Governing Equations Mihail CFX 7 September 7, 2014 06:27
Pressure enigma. Sara Main CFD Forum 22 July 30, 2009 04:46
How to get the pressure force on a surface? Jimmy Siemens 5 January 25, 2008 05:54
Hydrostatic pressure in 2-phase flow modeling (CFX4.2) HB &DS CFX 0 January 9, 2000 13:19


All times are GMT -4. The time now is 00:22.