[banji]

Hi Foamers,

Please how do I increase the number of parcels in the domain while keeping the total mass introduced by the end of the simulation fixed (as described in dict).

Please note that this is a non-reacting case.


Thanks.

[kmefun]

It might be done by increasing parcelsPerSecond in injectionModels?

[banji]

Thanks Kaufman for the reply.

I have tried your suggestion but it does not work. Infact it gets worse as the mesh is refined i.e. there is a huge drop in total mass after injection.

Could it be a bug - I use OpenFoam-2.3.x by the way

[kmefun]

Hi,

Could you post your injectionModels setup?

[banji]

Sure. Please find below:

injectionModels
{
//for each model, see src/lagrangian/.. for more details
model1
{
type coneNozzleInjection;
SOI 0;
massTotal 2.995e-6; //6.0e-6; //total mass to inject
parcelBasisType mass; //number, mass or fixed
injectionMethod disc;
flowType flowRateAndDischarge;
outerDiameter 93.8e-6; //1.9e-4;
innerDiameter 0;
duration 1.6998e-3; //1.25e-3;
position ( 0 0.0495 0 );
direction ( 0 -1 0 );
parcelsPerSecond 20000000; //# of parcels introduced per second
flowRateProfile table
(
/*(0 0.1272)
(0.00125 3.9213)
(0.001251 0.0000)
(1000 0.0000)
*/
(0 0)
(0.0000002 0.0000431032566444)
(0.0000004 0.0000862040320794)
(0.0000006 0.000129302344916)
(0.0000008 0.000172398213715)
(0.000001 0.000215491656984)
(0.0000012 0.000258582693178)
.
.
.
(0.0016982 0.000132313987523)
(0.0016984 0.000117619006053)
(0.0016986 0.000102922371616)
(0.0016988 0.0000882240883514)
(0.001699 0.0000735241604361)
(0.0016992 0.0000588225920867)
(0.0016994 0.0000441193875571)
(0.0016996 0.0000294145511397)
(0.0016998 0.0000147080871646)
(0.0017 0.0)
(1000 0.0000)
);

Cd constant 0.88; //0.9;

thetaInner constant 0.0;
thetaOuter constant 10.0;

sizeDistribution
{
type RosinRammler;

RosinRammlerDistribution
{
minValue 1e-06;
maxValue 0.00015;
d 0.00015;
n 3;
}
}
}
}

Also find below an excerpt of my log file - after injection has taken place

Solving 3-D cloud sprayCloud
Cloud: sprayCloud
Current number of parcels = 0
Current mass in system = 0
Linear momentum = (0 0 0)
|Linear momentum| = 0
Linear kinetic energy = 0
model1:
number of parcels added = 4037
mass introduced = 7.25864e-07
Parcels absorbed into film = 0
New film detached parcels = 0
Parcel fate (number, mass)
- escape = 0, 0
- stick = 0, 0
Temperature min/max = 0, 0
Mass transfer phase change = 7.25864e-07
D10, D32, Dmax (mu) = 0, 0, 0
Liquid penetration 95% mass (m) = 0

You'd observe that the mass introduced is not even close to what I specified in the subdict. Also the number of parcels are just too small to get any reasonable result.

Thanks again.

[banji]

I think I have resolved the problem. I observed that when running a sprayFoam case in parallel, the way the computational domain is decomposed has a great influence on the result. I am not sure if this has been resolved in later versions but for those using OF2.3. and OF2.4 (or previous), you might notice similar problems.

My take: Decompose the domain such that the injector cell is entirely in one of the sub-domains.

[slint]

Hello banji,

I can confirm this bug (and your solution) for OpenFOAM-2.4.x!

Best regards