CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Post-Processing

velocity is too fast (?)

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 29, 2010, 10:33
Default velocity is too fast (?)
  #1
Senior Member
 
Join Date: Aug 2010
Location: Groningen, The Netherlands
Posts: 216
Rep Power: 18
colinB is on a distinguished road
Hi
I'm not sure whether this is the right topic or not for I assume the failure is some where in the pre processoring part, but I discovered it in the post processing part, so I write it down here.

The problem:
I run a simulation with the rasInterFoam solver
The case is fairly simple a floating structure in a domain that is divided in an air part and a water part. The water shall enter the domain with a speed of 8m/s through an inlet patch and leave it through an outlet patch.
to quickly see if everything works out fine before I really let the simulation run I choose a total simulation time of 0.03 in the steps of 0.001 starting with 0.
According to simple mathematics a piece of wood starting at the inlet can travel only 0.24m within that given time and speed, neglecting any side effects.
But according to paraview it traveled around 40m and more.

So my question is: what?? how can that be??

I attached a file showing the paraview visualization
key data
domain size in x direction 350 m
velocity 8 m/s
timestep 0.03 is printed

If you have some further questions do not hesitate to ask me

thanks for your trouble


regards
Colin
Attached Images
File Type: jpg velocity_to_fast.jpg (50.4 KB, 8 views)
colinB is offline   Reply With Quote

Reply


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
ATTENTION! Reliability problems in CFX 5.7 Joseph CFX 14 April 20, 2010 15:45
Velocity in Porous medium : HELP! HELP! HELP! Kali Sanjay Phoenics 0 November 6, 2006 06:10
How to calculate Velocity? Kali Sanjay Phoenics 1 May 1, 2006 13:57
what the result is negatif pressure at inlet chong chee nan FLUENT 0 December 29, 2001 05:13
particle velocity and velocity profile HGG FLUENT 2 June 10, 2001 16:32


All times are GMT -4. The time now is 07:13.