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

some very basic questions

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

Reply
 
LinkBack Thread Tools Display Modes
Old   December 4, 2005, 22:13
Default some very basic questions
  #1
bomario
Guest
 
Posts: n/a
i was using Fluent Flow Lab for the first time today for an assignment. I was modeling a pipe, 0.1 m diameter and 20 m long. There was a template already set up that had all the values in it that we were supposed to use. The assignment required changing the inlet velocity (using guess and check) to obtain values of Reynolds number ranging from 200 to 1000. Then create the mesh (meduim density), iterate it, and plot the Frictional function. This produces a plot showing the friction vs. x (distance on the pipe). Then compare the fully developed frictional function to the theoretical, f=64/R.

My answers for each of the Reynolds numbers were very close to the theoretical so i think i did it right.

My questions are: 1. Why do i have to close and restart flowlab each time i want to do a different reynolds number. If i just went back and changed my geometery, it would keep showing the old frictional plot and not generate a new one.

2. What do the (x/D) values in the "start" window mean? i left these as the default, but i'm not sure if i was supposed to change them.

3. What does iterate do? the tutorial i was given did not mention this function, but i had to do the iteration first to get the right answer.

4. Not exactly sure what fully developed means? Does this mean when the frictional value stops changing--thats what i think i means. Is there an exact point, or do you just go by looking at it?

THANKS

  Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Basic questions on CFD theory CThib Main CFD Forum 12 October 17, 2011 08:50
FSI problem , Help needed for my basic questions kmgraju CFX 1 July 29, 2011 00:04
Very basic questions for ICEM CFD icemcfd ANSYS 2 December 21, 2010 17:01
LES basic and simple questions. dshawul Main CFD Forum 0 October 4, 2010 10:56
total newbie - Basic Questions caslor Main CFD Forum 9 December 10, 2009 12:49


All times are GMT -4. The time now is 17:43.