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

Search Results

Register Blogs Community New Posts Updated Threads Search

Showing results 1 to 25 of 25
Search took 0.00 seconds. Search: Posts Made By: niklas
Forum: OpenFOAM Running, Solving & CFD February 9, 2009, 05:49
Replies: 98
Views: 18,743
Posted By niklas
your initial drop-size is too

your initial drop-size is too small.
Forum: OpenFOAM Running, Solving & CFD July 11, 2008, 04:23
Replies: 98
Views: 18,743
Posted By niklas
So the differences are... Y

So the differences are...

Your pressure and temperature are 50 bar and 800K. With droplets of that size they wont go very far in such high density gas since the influence of the gas is quite...
Forum: OpenFOAM Running, Solving & CFD July 10, 2008, 02:40
Replies: 98
Views: 18,743
Posted By niklas
gravity? Its impossible for m

gravity?
Its impossible for me to say with the info I have.
Best thing for you would be to attach the case.
Forum: OpenFOAM Running, Solving & CFD July 9, 2008, 09:47
Replies: 98
Views: 18,743
Posted By niklas
You now have more than 1 injec

You now have more than 1 injector.
You have not specified spray angle and drop/nozzle -ratio for the second injector.
Thats what the error message is telling you.
'Wrong number of entries in...
Forum: OpenFOAM Running, Solving & CFD July 9, 2008, 08:32
Replies: 98
Views: 18,743
Posted By niklas
try removing the words inject

try removing the words
injector1
injector2
injector3

Im guessing you will be back soon after that is solved http://www.cfd-online.com/OpenFOAM_Discus/clipart/happy.gif
Forum: OpenFOAM Running, Solving & CFD July 8, 2008, 03:31
Replies: 98
Views: 18,743
Posted By niklas
Have you looked at what spray

Have you looked at what spray angle you have specified in the sprayProperties?
Forum: OpenFOAM Running, Solving & CFD July 4, 2008, 05:05
Replies: 98
Views: 18,743
Posted By niklas
There is a possibility that yo

There is a possibility that you might experience some weird effects if your drops are too small.

In the file
OpenFOAM-1.4.1/src/lagrangian/dieselSpray/parcel/parcel.C

you have this...
Forum: OpenFOAM Running, Solving & CFD July 4, 2008, 04:37
Replies: 98
Views: 18,743
Posted By niklas
you are using unitInjector to

you are using unitInjector to inject and
for this case that is not a very good idea, since
massFlowRate and injector diamerer is used to
calculate the injection velocity.

Here's what you...
Forum: OpenFOAM Running, Solving & CFD July 2, 2008, 06:56
Replies: 98
Views: 18,743
Posted By niklas
Oh... And you need to be care

Oh...
And you need to be careful so that the area under each injection occasion in the massFlowRateProfile is the same, otherwise the parcels will not contain the same mass.
Forum: OpenFOAM Running, Solving & CFD July 2, 2008, 06:23
Replies: 98
Views: 18,743
Posted By niklas
Actually, this is better mass

Actually, this is better
massFlowRateProfile
(
(0.0 1.0)
(1.0e-7 0)

(1.000000e-3 0)
(1.000001e-3 1)
(1.000002e-3 0)
Forum: OpenFOAM Running, Solving & CFD July 2, 2008, 06:13
Replies: 98
Views: 18,743
Posted By niklas
No, you have misunderstood the

No, you have misunderstood the massFlowRateProfile.

The format of the massFlowRateProfile is
massFlowRateProfile
(
(time1 kgPers1)
(time2 kgPers2)
(time3 kgPers3)
)
Forum: OpenFOAM Running, Solving & CFD July 2, 2008, 02:22
Replies: 98
Views: 18,743
Posted By niklas
> So it is not possible to reg

> So it is not possible to regard a parcel as a
> class of droplets with a diameter lying in a
> certain region, e.g parcel 1 contains all droplets
> with a diameter between 5-10µm, parcel 2...
Forum: OpenFOAM Running, Solving & CFD July 1, 2008, 09:21
Replies: 98
Views: 18,743
Posted By niklas
There is only 1 way to get mor

There is only 1 way to get more drops than what you have set nParcels to and that is of course the breakup.

However....

In the second case you are injecting liquid for 10ms and you are only...
Forum: OpenFOAM Running, Solving & CFD June 30, 2008, 07:41
Replies: 98
Views: 18,743
Posted By niklas
As expected I had no problem i

As expected I had no problem inserting only 1 drop...
Here's a working case.
http://files.nequam.se/drop.tgz

Here's a small helper application that will write the density of the liquid fuel...
Forum: OpenFOAM Running, Solving & CFD June 30, 2008, 06:13
Replies: 98
Views: 18,743
Posted By niklas
Its not particles that you spe

Its not particles that you specify, its parcels.
Important distinction, since a parcel can contain anything from 0.11231 to ..oh... 1231213100123.812 number of drops, i.e
mParcel = N*mDrop, where...
Forum: OpenFOAM Running, Solving & CFD June 27, 2008, 06:12
Replies: 98
Views: 18,743
Posted By niklas
massFlowRateProfile (or any ot

massFlowRateProfile (or any other profile) has to have at least 2 arguments.
the first is start-of-injection
and the last is end-of-injection.

if you only want 1 parcel you should do...
Forum: OpenFOAM Running, Solving & CFD March 19, 2007, 01:39
Replies: 98
Views: 18,743
Posted By niklas
Yes, it is DME.

Yes, it is DME.
Forum: OpenFOAM Running, Solving & CFD December 7, 2006, 04:44
Replies: 98
Views: 18,743
Posted By niklas
That is correct. The position

That is correct.
The position of the injection point is randomly chosen within the circle defined by injector position and diameter of injector.
Forum: OpenFOAM Running, Solving & CFD September 11, 2006, 07:22
Replies: 98
Views: 18,743
Posted By niklas
You have two constructors, one

You have two constructors, one where the
As and Ts are given, the other where they are
calculated using 2 viscosities and temperatures.

However, for the chemkin reader, all the transport...
Forum: OpenFOAM Running, Solving & CFD September 8, 2006, 05:42
Replies: 98
Views: 18,743
Posted By niklas
the viscosity and thermal diff

the viscosity and thermal diffusivity is calculating using sutherland's law,

take a look in src/thermophysicalModels/specie/transport/...

Mass diffusion is calculated using a Schmidt number...
Forum: OpenFOAM Running, Solving & CFD September 22, 2005, 10:23
Replies: 98
Views: 18,743
Posted By niklas
If you solve for ddt(alpha*rho

If you solve for ddt(alpha*rhoa*Ua) = ...
you'll end up with numerical problems as alpha->0, since you essentially will be solving a system 0=0.
Usually this is delt with by just setting alpha to...
Forum: OpenFOAM Running, Solving & CFD September 22, 2005, 06:42
Replies: 98
Views: 18,743
Posted By niklas
bubbleFoam I would say, You'l

bubbleFoam I would say,
You'll end up with alot of problems near the nozzle if you dont do it 'old Henry's' way.

You should take a look at how he eliminates the void-fraction from the...
Forum: OpenFOAM Running, Solving & CFD September 22, 2005, 06:02
Replies: 98
Views: 18,743
Posted By niklas
It isnt, because it is assumed

It isnt, because it is assumed that the spray is 'thin'.

N
Forum: OpenFOAM Running, Solving & CFD June 14, 2005, 08:36
Replies: 98
Views: 18,743
Posted By niklas
> The name of my interesting o

> The name of my interesting oil are coconut oil, palm oil and sun flower oil.
> Do you mean these name or chemical name?

Yes, but as i said, I can only treat single-component liquids, or...
Forum: OpenFOAM Running, Solving & CFD June 14, 2005, 03:53
Replies: 98
Views: 18,743
Posted By niklas
Hi, Yes, surface tension i

Hi,

Yes, surface tension is of some importance in sprays http://www.cfd-online.com/OpenFOAM_Discus/clipart/happy.gif

all liquids and their properties are located in...
Showing results 1 to 25 of 25

 
Forum Jump

All times are GMT -4. The time now is 06:08.

Contact Us - CFD Online - Privacy Statement - Top