CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLOW-3D

surface profile

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 27, 2011, 02:32
Question surface profile
  #1
New Member
 
navid maroofi
Join Date: Jul 2011
Posts: 3
Rep Power: 6
navid.maroofi is on a distinguished road
I am studing about self aeration on open channels with Flow-3d softeware.I want to ask a problem about surface profile. I solve one geometry of slope with 15 degree and q=1m^3/s with ks=.001 with step by step method and run it with flow-3d for this problem but I cant match these result. flow-3d gives much bigger rusult. can anybody help me to find why flow-3d cant give the good result about surface profile?

Last edited by navid.maroofi; July 27, 2011 at 03:13.
navid.maroofi is offline   Reply With Quote

Old   July 29, 2011, 00:22
Default
  #2
Senior Member
 
michael barkhudarov
Join Date: Mar 2009
Posts: 331
Rep Power: 9
MuxaB is on a distinguished road
Quote:
Originally Posted by navid.maroofi View Post
I am studing about self aeration on open channels with Flow-3d softeware.I want to ask a problem about surface profile. I solve one geometry of slope with 15 degree and q=1m^3/s with ks=.001 with step by step method and run it with flow-3d for this problem but I cant match these result. flow-3d gives much bigger rusult. can anybody help me to find why flow-3d cant give the good result about surface profile?
What are the inlet/outlet BC?
MuxaB is offline   Reply With Quote

Old   July 29, 2011, 03:34
Default
  #3
New Member
 
navid maroofi
Join Date: Jul 2011
Posts: 3
Rep Power: 6
navid.maroofi is on a distinguished road
I tried 3 types for inlet Bc. but didnt catch good result yet:
1.specified pressure with height "11.6" (m) with vent that open "0.35" (m)
2.specified velocity, u=2.64 (m/s) & w= -1.093 (m/s) ,h=11.07
3.volume flow rate, q=1 (m^3/s), x flow direction vector=1 , z flow direction vector= -0.2679
and continuative for outlet BC.
The geometry has 40 (m) lenghth and 10.72 (m) height-15 degree-
The normal depth is near 0.108 m with formula but with flow3d is near 0.2 m.why?

Last edited by navid.maroofi; July 29, 2011 at 03:54.
navid.maroofi is offline   Reply With Quote

Old   August 1, 2011, 07:08
Default
  #4
Member
 
Armen A. Ghirghidov
Join Date: Mar 2009
Posts: 50
Rep Power: 8
Ghirghidov is on a distinguished road
Dear navid maroofi.

Try to use outflow BC. BTW 2 and 3 is not quite correct BC.

Regards.
Ghirghidov is offline   Reply With Quote

Old   August 1, 2011, 09:59
Default
  #5
New Member
 
navid maroofi
Join Date: Jul 2011
Posts: 3
Rep Power: 6
navid.maroofi is on a distinguished road
Quote:
Originally Posted by Ghirghidov View Post
Dear navid maroofi.

Try to use outflow BC. BTW 2 and 3 is not quite correct BC.

Regards.
i used that but no change happend because our flow is supercritical and control from up
navid.maroofi is offline   Reply With Quote

Old   August 2, 2011, 04:06
Default
  #6
Member
 
Armen A. Ghirghidov
Join Date: Mar 2009
Posts: 50
Rep Power: 8
Ghirghidov is on a distinguished road
Will roughness affect?
try to use another mesh. for example number of cells across channel are integer.

regards.
Ghirghidov 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
Thermocapillary free surface flow zakifoam OpenFOAM Running, Solving & CFD 6 August 24, 2014 03:24
Different surface incident radiation between surface and surface-shadow Cortomaltese FLUENT 0 July 16, 2011 07:00
[ICEM] Automatic mesh generation script surface intersection problem stuart23 ANSYS Meshing & Geometry 0 May 13, 2011 01:10
Normal - Helical Surface m. malik Main CFD Forum 3 February 3, 2006 13:56
Flame Surface Density. Burn Ing Main CFD Forum 3 December 5, 2004 18:12


All times are GMT -4. The time now is 14:55.