|
[Sponsors] |
April 13, 2004, 03:22 |
discrete phase Boundary condition
|
#1 |
Guest
Posts: n/a
|
hai
In my problem for non-premixed combustion, I am sending coal by using "release from surfaces" option and taking coal inlet as the surface....now, what boundary condition shall I give for coal inlet in boundary conditions panel..."only coal is sent throught the coal inlet"/// air is coming from other inlet.... waiting for a kind response Prasanth |
|
April 13, 2004, 09:01 |
Re: discrete phase Boundary condition
|
#2 |
Guest
Posts: n/a
|
hi,
from my point of view you can use mass flow inlet as a boundary condition for coal. let me know if this helps regards David |
|
April 13, 2004, 09:53 |
Re: discrete phase Boundary condition
|
#3 |
Guest
Posts: n/a
|
hai
Thanks for your kind reply. I have given mass flow condition itself. I want to know which is reasonable: 'trap' or 'escape'. thanks and regards |
|
April 13, 2004, 10:16 |
Re: discrete phase Boundary condition
|
#4 |
Guest
Posts: n/a
|
Also I want to know what we have to specify for mean mixture fraction and variance>??
thanks in advance prasanth |
|
April 13, 2004, 21:23 |
Re: discrete phase Boundary condition
|
#5 |
Guest
Posts: n/a
|
I think trap means incomplete,escape means particle flow with fluid out of boundary
|
|
April 14, 2004, 01:04 |
Re: discrete phase Boundary condition
|
#6 |
Guest
Posts: n/a
|
Hello Sir
Thanx for your reply. But still we are having doubt with it. whether escape mode escapes out all the particles when it approaches the inlet/outlet boundary? If we don't want the particle to escape through some inlet/outlet, what type we have to select: "escape" or "trap"? when will we use the other mode "wall jet" (application?)? In defining discrete phase, we will specify velocity and flow rate for coal; is it needed to specify the mass flow rate at the mass flow inlet B C at coal-inlet? * In our case, at coal inlet,only coal goes into the chamber, not along with air. Air comes through other inlet. Regards Prasanth |
|
April 14, 2004, 02:53 |
Re: discrete phase Boundary condition
|
#7 |
Guest
Posts: n/a
|
I am sorry,I dcannot reply this question.In my cases particles come in with fluid.
|
|
April 14, 2004, 02:56 |
Re: discrete phase Boundary condition
|
#8 |
Guest
Posts: n/a
|
I think in fluent6.1'Tutorial 13: Using the Non-Premixed Combustion Model may give you some help.
|
|
April 14, 2004, 04:28 |
Re: discrete phase Boundary condition
|
#9 |
Guest
Posts: n/a
|
They also doing same thing as yours.
thank you sir |
|
April 14, 2004, 07:02 |
Re: discrete phase Boundary condition
|
#10 |
Guest
Posts: n/a
|
hi,
this is what FLuent's manual says: ``trap'' terminates the trajectory calculations and records the fate of the particle as ``trapped''. In the case of evaporating droplets, their entire mass instantaneously passes into the vapor phase and enters the cell adjacent to the boundary ``reflect'' rebounds the particle off the boundary in question with a change in its momentum as defined by the coefficient of restitution ``escape'' reports the particle as having ``escaped'' when it encounters the boundary in question. Trajectory calculations are terminated ``wall-jet'' means that the direction and velocity of the droplet particles are given by the resulting momentum flux, which is a function of the impingement angle, $\phi$, and Weber number. I didn't know wall jet. I think it is a new BC included into DPM in fluent. FLUENT assumes the following boundary conditions: * ``reflect'' at wall, symmetry, and axis boundaries, with both coefficients of restitution equal to 1.0 * ``escape'' at all flow boundaries (pressure and velocity inlets, pressure outlets, etc.) * ``interior'' at all internal boundaries (radiator, porous jump, etc.) I hope this helps regards David |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Boundary condition at phase interface | skp | OpenFOAM Programming & Development | 5 | February 12, 2017 20:51 |
inlet velocity boundary condition | murali | CFX | 5 | August 3, 2012 08:56 |
Mixed/Robin boundary condition | aaev | OpenFOAM Bugs | 2 | December 15, 2011 14:03 |
[Commercial meshers] Trimmed cell and embedded refinement mesh conversion issues | michele | OpenFOAM Meshing & Mesh Conversion | 2 | July 15, 2005 04:15 |
Pressure Boundary Condition | Matt Umbel | Main CFD Forum | 0 | January 11, 2002 10:06 |