sprayFoam
Hello!
I need a solver to visualized a liquid spray. As I see in tutorials of OF, one of solvers I can use is sprayFoam (I need only first 2 steps: spray breakup and spray tracking). At 1st I made a tutorial aachenBomb. the results are ok: filed of velocity and pressure seem to be real, but when I try to see particles [foamToVtk and then load sprayCloud], paraview closed with "Segmentation fault". UPD. On another machine paraview work ok,but I don't see any particles :(.It seems there are no particles. Does anyone know what do I do wrong? Maybe someone has a similar task and can help me. Another question: I found an information about CFDEM and LIGGGHTS. As I understand it is possible to solve my problem using it. But I didn't find any information of their tutorials. Maybe I compiled it not correct, but I didn't see any results after making tutorial cfdemSolverPiso/settlingTestMPI. Maybe someone can give me more information about it. |
Since you mentioned sprayFoam I'm assuming your are using OF 2.1.x. You should be able to just load the defaultCloud in ParaFoam and then extract it using the extractBlock filter. Try that and see what happens.
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About paraview: I made as you sad. Load defaultCloud (hope you mean spray.foam), then I used extractBlock filter. After that I choose in pipelan browser interanlMesh, but after it I can load velocity field and pressure field on the same picture together. But I didn't find particles. I copy from another directory ParticleTrackProperties in constant/ and use particleTracks. After that I have a directory VTK, inside it - particleTracks.vtk This file I load in paraview, then use Glyph filter - visible spheres. The results of my operation I attach. But I have a doubt - are they right? For my opinion tracks of particles are not right. Velocity field and pressure field are ok.Attachment 18554 Attachment 18555 |
Hi Akuji,
What are you scaling the glyph diameter by? Sometimes the distribution can look misleading because of a uniform diameter. Also, what does the temperature look like? |
evaporating_drops.ccl
Hi,
It is not related to spray foam but could you please send the tutorial file "evaporating_drops.ccl" It is for "Spray Dryer" tutorial? I need it so badly! alimecngz@gmail.com |
I don't have this tutorial case, I'm not sure what version of OpenFOAM it belongs to. Sorry
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it belongs to ANSYS CFX 13. Thanks anyway :)
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About temperature: at time 0.0015 there is no field of temp. Because I don't need a part of tutorial with combustion, I cut all times where there is no any injection of particles. The diameter of scaling is 1 (r=0.5). If I choose smaller radius, image is the same, just particles look smaller. |
I know you can scale the particles to be proportional to their mean diameter. Is there any evaporation happening?
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Hello!
About evaporation - really I don't know. The last time when parcels are added is t=0.0125: Time = 0.00125 Solving cloud sprayCloud --> Cloud: sprayCloud Added 56 new parcels Cloud: sprayCloud Current number of parcels = 18944 Current mass in system = 4.12019e-07 Linear momentum = (-1.64279e-07 -3.21616e-05 -3.42757e-08) |Linear momentum| = 3.21621e-05 Linear kinetic energy = 0.0025296 Rotational kinetic energy = 0 Total number of parcels added = 123490 Total mass introduced = 5.99999e-06 Parcel fates: - escape = 0, 0 - stick = 0, 0 Mass transfer phase change = 5.58798e-06 D32 (mu) = 6.71635 Liquid penetration 95% mass (m) = 0.0193151 As I understand, evaporation exist, because current number of parcels if 18 944, and total number of parcels added is 123 490. Another step I did, i finally understand how to use vtk file for my time. The spray seems to be real. Question I have: how to see the distribution of parcels according to their diameter? D32 is 6.7e-6m (am I right?). So, to see the particles I use glyph type sphere, radius = 1, scale mode = 6.7e-6. And my particles have one size and one color. |
I would also plot the mass fraction of what is evaporating. If all the particles are constant diameter, then the distribution looks feasible, since parcels break up as we leave the nozzle, increasing the number of parcels while evaporation reduces the number.
I would also plot the mass fraction of the species that is evaporating in the droplets. |
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Well, after some weeks of solving I still have questions.
1. How does sprayFoam calculate D32? According to my calculation I have particles size 1.3mm, and foam calculate as 21581.9 (*10^-6 am I right?). 2. I don't need an evaporation, combustion, chemiacl reactions and other parts. I am interested only in the particle size, path and the particle interaction and particle-to-wall interactions. I turn off evaporation, combustion and etc., change chem.inp file but still have dependence of Temperature: Code:
DILUPBiCG: Solving for hs, Initial residual = 0.000893686, Final residual = 1.45528e-10, No Iterations 1 So, example of output in my terminal: Code:
Cloud: sprayCloud If you have an idea or any free time, please, see my attached files: I think there are some mistakes too. |
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Check the Dij-function, D32 = Dij(3,2) The biggest droplets are around 0.1m...which i think probably is a mistake. Quote:
How much time have elapsed and how much water are you supposed to inject, because that looks like quite alot. (remember that injected mass is in kg) |
remember also that length is in meters, not millimeters
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niklas,
thank you for your help. I find Dji in KinematicCloudI.H, but didn't understand how it calculates (my c++ knowledge is very bad). But I see then more I have mass flow then less diametr my particles have. About Dmax: I don't know exactly how solver works, but in my work I have drops of water. They interract between themselves: can divide or couple for more smaller or larger particle. Dmax=0.1m is probably puddle on the floor or on the wall (it is my explanation why it is so large). I reviewed my b.c. and my mass flow is ok (I plan to inject 10 kg/s from my nozzle). My mesh is in meters. |
Hello again!
A added a Blob Atomization model for primary break-up, but have no difference with my previous effort. Now I have a problem: when my particles reach disk they have absolutely elastic impact. They fly to the patch which from they fall. And for them it is not important that it is injection still work. In fluent I have very nice results for my room, but in OF there is no any spray dissemination :( Any ideas?.. http://www.ljplus.ru/img4/f/u/fucking_blondy/age.jpg |
Really sad, but particles just bounce between out-patch and disk-patch :(
http://www.ljplus.ru/img4/f/u/fucking_blondy/100.jpg |
Hi Akuji, I don't understand how visualize in paraview particles in the spray cloud for aachen bomb tutorial; I've used foamToVTK to create VTK files but when I select spraycloud.vtk and I choose glyph,I don't see the particles.Can you explain me the procedure?
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In the example I load spraycloud.vtk, choose glyph: type - sphere and scale mode - scalar, then apply. If you still don't see particles, try to edit scalar factor: for example, use not 0.002 but 0.02 - you will see difference. And use for example time=11, not 0 or 1. Good luck! |
sprayCloudProperties
Hello friends... in this moment I'm studying the code of sprayFoam and I don't know what means de "youngsModulus" and "poissonRatio" at the file sprayCloudProperties, this properties belong to what substance? the liquid or the ambient gas?
Thanks . |
sprayFoam / dsmcFoam
Is it correct to think that sprayFoam is based on DSMC method?
In that case why there is a separate solver dsmcFoam? Is the distinction on basis of solid vs liquid particles? |
How can I plotting the Vapor penetration after simulation sprayFoam
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It is very late but I am facing same problem of bouncing back. Have you find solution? Please Help. |
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localInteractionCoeffs { patches ( TopWall { type rebound; e 0.97; mu 0.09; } Walls { type rebound; e 0.97; mu 0.09; } BottomWall { type escape; } ); } that is my idea define the patch which one need for bouncing and which one need to be escape |
gas turbine spray combustion using sprayFoam
I am using sprayFoam for simulating spray combustion. I have modified the aachenBomb case and it is running.
How can I include OH to my chemkin files so that i can visualise the flame contours as well during my post processing? |
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