|
[Sponsors] |
icoUncoupledKinematicParcelFoam - strange thing |
![]() |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
![]() |
![]() |
#1 |
Super Moderator
Tobias Holzmann
Join Date: Oct 2010
Location: Bad Wörishofen
Posts: 2,712
Blog Entries: 6
Rep Power: 52 ![]() ![]() ![]() |
Hi all,
I am building an hydro-cyclone and simulated it with simpleFoam. Now I want to add particels and want to use the solver icoUncoupledKinematicParcelFoam. The solver is adding particels but after 4 added - no particel is in the domain anymore?: Code:
Time = 0.006 Evolving kinematicCloud Solving 3-D cloud kinematicCloud 531 move-collide subCycles Cloud: kinematicCloud Current number of parcels = 2 Current mass in system = 0.000916088 Linear momentum = (0.000388678 0.00668253 0.00395061) |Linear momentum| = 0.00777268 Linear kinetic energy = 0.0574843 Rotational kinetic energy = 0.0325214 model1: number of parcels added = 2 mass introduced = 0.000916088 Parcels absorbed into film = 0 New film detached parcels = 0 ExecutionTime = 606.33 s ClockTime = 628 s Time = 0.0061 Evolving kinematicCloud Solving 3-D cloud kinematicCloud --> Cloud: kinematicCloud injector: model1 Added 1 new parcels 530 move-collide subCycles Cloud: kinematicCloud Current number of parcels = 0 Current mass in system = 0 Linear momentum = (0 0 0) |Linear momentum| = 0 Linear kinetic energy = 0 Rotational kinetic energy = 0 model1: number of parcels added = 3 mass introduced = 0.00137413 Parcels absorbed into film = 0 New film detached parcels = 0 ExecutionTime = 615.79 s ClockTime = 638 s Well I have not many experiance with that solver - especially with the settings I have to make in the Cloud file. I showed the variables in red I am not 100% sure of the meaning. Maybe someone can clear my mind: My file is the following: Code:
solution { active true; coupled false; transient yes; cellValueSourceCorrection off; interpolationSchemes { rho cell; U cellPoint; mu cell; } integrationSchemes { U Euler; } } constantProperties { rho0 1.2; // Air + particel load ? youngsModulus 6e8; // not sure about poissonsRatio 0.35; // not sure about } subModels { particleForces { sphereDrag; gravity; } injectionModels { model1 { type patchFlowRateInjection; patchName inlet; duration 2; concentration 0.6; // parcel concentration in my fluid? parcelsPerSecond 500; meanParticleDiameter 0.003; // for what? nParticle 1000; // max particle in domain ? massTotal 0.5; // max mass in the domain ? parcelBasisType fixed; // dont know SOI 0; // ? sizeDistribution { type fixedValue; // particle have fixed sizes fixedValueDistribution // the sizes the particels can have ? { value 0.006; value 0.01; value 0.001; value 0.015; value 0.004; value 0.009; } } } } dispersionModel none; patchInteractionModel none; surfaceFilmModel none; collisionModel pairCollision; pairCollisionCoeffs { maxInteractionDistance 0.006; writeReferredParticleCloud no; pairModel pairSpringSliderDashpot; pairSpringSliderDashpotCoeffs { useEquivalentSize no; alpha 0.12; b 1.5; mu 0.52; cohesionEnergyDensity 0; collisionResolutionSteps 12; }; wallModel wallLocalSpringSliderDashpot; wallLocalSpringSliderDashpotCoeffs { useEquivalentSize no; collisionResolutionSteps 12; ".*Wall" { youngsModulus 1e10; poissonsRatio 0.23; alpha 0.12; b 1.5; mu 0.43; cohesionEnergyDensity 0; } }; } } Are there any tutorials available (not the hopper one?) Maybe I have to use a other particel solver for my problem? Thanks in advance Tobi |
|
![]() |
![]() |
![]() |
![]() |
#2 |
New Member
liyu
Join Date: Jan 2014
Location: Beijing
Posts: 10
Rep Power: 13 ![]() |
hello, Tobi.
actually, i can not help you very much, because i am a rookie. but i know, "SOI" means " start of injection". specifically, in your code, it means model1 begins to inject particles at 0 second. " nParticle" means the number of particles that one parcel contains. "massTotal" dose not determine anything when you set the "parcelBasicType" as "fixed". ok, that is all i can do for you. best regards. |
|
![]() |
![]() |
![]() |
![]() |
#3 |
New Member
liyu
Join Date: Jan 2014
Location: Beijing
Posts: 10
Rep Power: 13 ![]() |
hello, Tobi.
actually, i can not help you very much, because i am a rookie. but i know, "SOI" means " start of injection". specifically, in your code, it means model1 begins to inject particles at 0 second. " nParticle" means the number of particles that one parcel contains. "massTotal" dose not determine anything when you set the "parcelBasicType" as "fixed". ok, that is all i can do for you. best regards. |
|
![]() |
![]() |
![]() |
![]() |
#4 |
Member
ziehjay
Join Date: Jul 2013
Posts: 45
Rep Power: 13 ![]() |
Hello Tobias,
i guess we know each other. ![]() Code:
constantPoperties youngsModulus 6e8; // E-Modul poissonsRatio 0.35; // Poissonzahl Code:
nParticle: total amount of particles you want to inject massTotal: total mass of the particles in kg SOI: Start of Injection (when particles are loaded on the streamlines of your main-fluid-flow pairCollisionCoeffs maxInteractionDistance: maximal distance of action between particles (max. Beeinflussungsdistanz) wallModel wallLocalSpringSliderDashpot: describes the influence of particle with the wand (Partikel-WandStoß) collisonReslutionSteps 12 youngsModuls: E-Modul b: Federgesetzexponent alpha: Restitution coefficient poissonsRatio: Poissonnumber mu: Reibungskoeffizient cohesionEnegryDistance: Bindungsenergie [J/m³] Greetings, Sanjar |
|
![]() |
![]() |
![]() |
![]() |
#5 |
New Member
Join Date: Jul 2015
Posts: 17
Rep Power: 11 ![]() |
Hi Tobias,
Were you able get answers to your doubts? I am interested to know. |
|
![]() |
![]() |
![]() |
![]() |
#6 |
New Member
Ronith Stanly
Join Date: Mar 2017
Location: Sweden
Posts: 24
Rep Power: 9 ![]() |
Hi Sanjar,
The information you provided on this topic is quite useful however, I found an error and I would like to mention it so that others won't end up disappointed after simulating and probably they will not have to endlessly try different settings to find the bug. The "alpha" is not equal to the coefficient of restitution, but they are related as shown in Fig.4 page 243 of Y. Tsuji, T. Tanaka, T. Ishida, Lagrangian numerical simulation of plug flow of cohesionless particles in a horizontal pipe, Powder Technology, Volume 71, Issue 3, September 1992, Pages 239-250, ISSN 0032-5910, https://doi.org/10.1016/0032-5910(92)88030-L. (http://www.sciencedirect.com/science...3259109288030L) For example (taken from that graph), if Coefficient of Restitution=1, then alpha=0.01. Hope this will help some others ![]() Regards, Ronith Stanly |
|
![]() |
![]() |
![]() |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Strange Nut behaviour with K-OmegaSST | nicolarre | OpenFOAM Running, Solving & CFD | 12 | March 19, 2019 21:35 |
Strange residuals behaviour | xxxx | Main CFD Forum | 1 | July 13, 2013 15:40 |
A strange thing on Compaq Visual Fortran | archdevil | Main CFD Forum | 7 | May 17, 2012 07:38 |
A Strange Problem in making Parallel (Ansys/CFX 12) | a.sarami | CFX | 13 | October 7, 2010 02:33 |
Strange things in SRF (urgent) | Cem | FLUENT | 0 | December 19, 2005 11:37 |