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

Drag and lift coefficient for hydrofoil

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 25, 2013, 21:47
Talking Drag and lift coefficient for hydrofoil
  #1
New Member
 
Lee,Dong Beom
Join Date: Apr 2013
Posts: 21
Rep Power: 4
ldb83 is on a distinguished road
Hello

I am studying oscillating hydrofoil in water.

I have used k-e model and the frequency and amplitude of hydrofoil are 1.25Hz and 1.0m.

Also I used PISO for solution method.
time step is 0.001s and number of time step is 800.

and when I checked the drag coefficient, the values are between 10000~-80000.

Originally, I have expected the value near 1.0.

I am wondering I have made some mistake in my model or the values are true?

Is there any one who could give me valuable comment?

Have a nice day all~
Attached Images
File Type: jpg boundary condition.jpg (91.1 KB, 16 views)
File Type: jpg colution method.JPG (60.4 KB, 13 views)
File Type: jpg drag coefficient.JPG (56.0 KB, 15 views)
File Type: jpg mesh.JPG (40.7 KB, 12 views)
File Type: jpg model.JPG (83.5 KB, 13 views)
ldb83 is offline   Reply With Quote

Old   June 28, 2013, 16:27
Default Answer
  #2
Member
 
sadjad.s's Avatar
 
sadjad
Join Date: Jan 2012
Posts: 60
Rep Power: 5
sadjad.s is on a distinguished road
Send a message via Yahoo to sadjad.s
Hi mate,
Did you revise "Referece Values"?
__________________
ICEM, CFX and Fluent expert
sadjad.s is offline   Reply With Quote

Old   July 2, 2013, 01:58
Default
  #3
New Member
 
Lee,Dong Beom
Join Date: Apr 2013
Posts: 21
Rep Power: 4
ldb83 is on a distinguished road
Quote:
Originally Posted by sadjad.s View Post
Hi mate,
Did you revise "Referece Values"?
Hi

When I review my reference value, I can't find any strange point.
Attached Images
File Type: jpg refer.JPG (23.4 KB, 6 views)
ldb83 is offline   Reply With Quote

Old   July 2, 2013, 03:03
Default Answer
  #4
Member
 
sadjad.s's Avatar
 
sadjad
Join Date: Jan 2012
Posts: 60
Rep Power: 5
sadjad.s is on a distinguished road
Send a message via Yahoo to sadjad.s
It seems that you left default values and that's the problem.
What indicated in Reference values are just used in calculation of some Dimensionless numbers such as Drag and Lift coefficients.
As an example, for drag coefficient, you should revise Velocity, area and density.
__________________
ICEM, CFX and Fluent expert
sadjad.s is offline   Reply With Quote

Old   July 2, 2013, 03:17
Default
  #5
New Member
 
Lee,Dong Beom
Join Date: Apr 2013
Posts: 21
Rep Power: 4
ldb83 is on a distinguished road
Quote:
Originally Posted by sadjad.s View Post
It seems that you left default values and that's the problem.
What indicated in Reference values are just used in calculation of some Dimensionless numbers such as Drag and Lift coefficients.
As an example, for drag coefficient, you should revise Velocity, area and density.

Thank you so much for your kind reply.

I will modify the reference value based on the my study.

Your comment is very helpful for me.

Have a nice day~
ldb83 is offline   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
lift & drag coefficient on airfoil n. natik FLUENT 8 March 31, 2015 19:02
airfoil lift and drag coefficient amir_14 FLUENT 5 January 1, 2013 09:30
Drag and Lift coefficient for diffusor rego STAR-CCM+ 3 May 7, 2012 18:05
Automotive test case vinz OpenFOAM Running, Solving & CFD 98 October 27, 2008 09:43
drag and lift coefficient No CD-adapco 5 July 13, 2004 10:21


All times are GMT -4. The time now is 11:12.