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

Problem in generating linear Wave !?

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 29, 2012, 04:05
Default Problem in generating linear Wave !?
  #1
New Member
 
hoannv
Join Date: Apr 2011
Posts: 8
Rep Power: 14
mystar is on a distinguished road
Dear all,
I am trying to generate linear Wave in CFX,..
I all so make following conditions:
@Inlet : i applied velocity at Ui and Vi ; and Fluid Values: water= WaterI
@Outlet: Relative Pressuer is Hypers, Fluid value is Zero gradient
WaterI = if(y<WaterSurface, 1, 0)
Hypres= if(y >WaterSurface, 0[Pa], (997-1.185)*g*(WaterSurface-y))
WaterSurface = 0,5*H*Cos(2*pi*(x/L-t/T))
Ui = pi*H /T *cosh(2*pi*(y+d)/L )*cos(2*pi*(x/L -t/T))/cosh(2*pi*d/L )
Vi = pi*H /T *sinh(2*pi*(y+d )/L )*sin(2*pi*(x/L -t/T))/sinh(2*pi*d /L )

H: wave height
L: wave length
T wave period
d: mean water depth


But, my result is non-reasonable,... Pls ponit me what is wrong ?

thank and sorry for my English
mystar is offline   Reply With Quote

Old   November 29, 2012, 17:20
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
If you want us to help you, you will have to describe what happened. What is not reasonable about it?
ghorrocks is offline   Reply With Quote

Old   November 29, 2012, 21:33
Default
  #3
New Member
 
hoannv
Join Date: Apr 2011
Posts: 8
Rep Power: 14
mystar is on a distinguished road
Quote:
Originally Posted by ghorrocks View Post
If you want us to help you, you will have to describe what happened. What is not reasonable about it?
Frist of all, i am wondering my applied boundary conditions right or wrong for linear wave ?
Followings describes my problem, The result is nonreasonable and i dont understand it

pls let me know what is wrong here !

Many thank and Brg
Attached Images
File Type: jpg Untitled.jpg (15.9 KB, 53 views)
File Type: jpg Untitled1.jpg (14.3 KB, 44 views)
mystar is offline   Reply With Quote

Old   November 30, 2012, 11:20
Default
  #4
Member
 
Peter
Join Date: Sep 2011
Location: Germany
Posts: 39
Rep Power: 14
PeMo is on a distinguished road
First seems like you didnt initialise the model. For 2-Phase transient flow it is necessary to define the area of water before the simulation. I did this 2D numerical wave channel thing in Fluent a couple of years ago, so the main problem is not to generate the waves, it is to get the waves out of the model. Fluent supported this with sth called numerical beach treatment, maybe you have similar functions in CFX. No ideas if your formulas are right but you have to differentiate between shallow and deep water waves, which you will find with the right formulars in every good book about free surface/open channel flow
PeMo is offline   Reply With Quote

Old   December 3, 2012, 23:13
Default
  #5
New Member
 
hoannv
Join Date: Apr 2011
Posts: 8
Rep Power: 14
mystar is on a distinguished road
Quote:
Originally Posted by PeMo View Post
First seems like you didnt initialise the model. For 2-Phase transient flow it is necessary to define the area of water before the simulation. I did this 2D numerical wave channel thing in Fluent a couple of years ago, so the main problem is not to generate the waves, it is to get the waves out of the model. Fluent supported this with sth called numerical beach treatment, maybe you have similar functions in CFX. No ideas if your formulas are right but you have to differentiate between shallow and deep water waves, which you will find with the right formulars in every good book about free surface/open channel flow
Dear Pemo and all, i also define the initialisation for each phase by Waterini expression... and i try to make another example by following attackment, file CFD-Online.ccl, but when i run it... the error "Floating point" is occured
Imagine define my model, CFD-Online.ccl define boundary condition i made... pls see and correct it

Thank so much !
Attached Images
File Type: jpg Untitled.jpg (13.2 KB, 33 views)
Attached Files
File Type: zip CFD-Online.zip (3.9 KB, 22 views)
mystar 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
[waves2Foam] Waves2Foam Related Topics ngj OpenFOAM Community Contributions 660 August 20, 2018 13:39
How to plot the wave contour in ship flow (free surface) problem deddy1973 CFX 6 February 19, 2013 06:49
generate linear wave in fluent happyqj FLUENT 1 March 18, 2012 05:25
Help! Compiled UDF problem 4 Wave tank tutorial Shane FLUENT 1 September 3, 2010 03:32
problem in solving "wave generation" problem san FLUENT 2 April 4, 2006 00:37


All times are GMT -4. The time now is 05:30.