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

MassFlow Function? Absolute MassFlow? Failure in Caclulation

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 5, 2011, 10:46
Default MassFlow Function? Absolute MassFlow? Failure in Caclulation
  #1
Senior Member
 
Join Date: Dec 2010
Posts: 135
Rep Power: 15
eRzBeNgEl is on a distinguished road
Hi guys

I posted a similar question a few months ago and I am trying it now again. I have a geometry with 2 Inlets where fluid can go in and out and also one Outlet on the side, where fluid can go in and out. (For a pic see in the attachement)

This is my problem

I want to calculate Percentage of the Massflow which is going inside the domain and coming out.

These are my 3 domoins
Interface_Top
Interface_Bottom
Interface_Side

I created an AbsInt for every Interface Expression:
AbsIntTop = areaInt(Density * abs(Velocity in Stn Frame w))@Interface_Top

I also used the CFX Massflow function for every surface.
MassFlowTop = massFlow()@Interface Top

If the MassFlow result is positive on Top Side (x-y Plane) it means that the Result is that part which is going inside the domain, which means that I can just say:

AbsInt - MassFlow = Fluidpart which is coming out again and not keeping inside

For the Interface_Side I used of course the radial velocity and not the Velocity w!

So these are my results:

AbsInt
AbsInt Interface Top 0,0073
IAbsInt nterface Bottom: 0.0057
AbsInt nterface Side: 0,0155

MassFlow
MassFlow Interface Top: 0,00626
MassFlow Interface Bottom:0,00562
MassFlowInterface Side: 0,0139

Let's do AbsInt - MassFlow for every Inteface.
Delta Interface Top 0,00104
Delta Interface Bottom 0,0001
Delta Interface Side 0,0016

These must be the part of the fluid which is a Loss. So If I sum up e.g.:
AbsInt Interface Top - Delta Interface Top + IAbsInt nterface Bottom - Delta Interface Bottom it should be MassFlowInterface Side

0,0073-0,00104+0,0057-0,0001 = 0,01186 which is NOT MassFlow InterfaceSide = 0,0139

Sorry for the complicated way to explain my question?

Need help! :-)

Thanks
Attached Images
File Type: jpg Velw1.jpg (53.2 KB, 11 views)
eRzBeNgEl 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
Compile problem ivanyao OpenFOAM Running, Solving & CFD 1 October 12, 2012 10:31
ParaView for OF-1.6-ext Chrisi1984 OpenFOAM Installation 0 December 31, 2010 07:42
latest OpenFOAM-1.6.x from git failed to compile phsieh2005 OpenFOAM Bugs 25 February 9, 2010 05:37
Error with Wmake skabilan OpenFOAM Installation 3 July 28, 2009 01:35
[blockMesh] Axisymmetrical mesh Rasmus Gjesing (Gjesing) OpenFOAM Meshing & Mesh Conversion 10 April 2, 2007 15:00


All times are GMT -4. The time now is 06:47.