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Evaporation due to Heat Transport using InterFoam (Correct Implementation?) 

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October 3, 2010, 05:10 
Evaporation due to Heat Transport using InterFoam (Correct Implementation?)

#1 
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Ovie Doro
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Hi,
I have tried to implement phase change due to evaporation for an incompressible liquid flowing down a vertical heated wall using interFOAM with an energy transport equation. I have employed the methods suggested by Bitan Shu (Phase Change Model for TwoPhase Fluid Flow Based on VOF Method) and Wondra et al. (Evaporation Model for Interfacial Flows Based on a Continuum Field Representation of the Source Terms). However in both cases, I am unable to accurately reproduce the results presented in their papers. I am particularly interested in Bitan Shu's implementation because it allows for large grid sizes. Has anyone successfully done this? If anyone has, please take a look at my code and tell me where I am wrong. Help is needed PLEASE! STEP 1: Solve the energy transport equation for the entire domain i.e. (both liquid and gas): STEP 2: Compute source terms using gradient of temperature: Code:
volVectorField gradAlpha = fvc::grad(alpha1); // to compute interface normal unit vector volVectorField nHat = gradAlpha/(mag(gradAlpha) + interface.deltaN()); // compute interfacial area = magnitude of grad(alpha1)*volume of cell volScalarField alpha1Prime = mag(gradAlpha); // set liquid and interfacial temperature to Tsat forAll(mesh.cells(), celli) { if (alpha1[celli] >= scalar(0.5)) { T[celli] = Tsat.value(); } // set this values to zero so that only liquid evaporation is accounted for if (alpha1[celli] < scalar(0.50)) { alpha1Prime[celli] = scalar(0); } } // Compute mass source field mDot = (kappa/evapEnthalpy)*(fvc::grad(T) & nHat)*alpha1Prime; // Compute energy source field using enthalpy of evaporation hDot = evapEnthalpy*mDot; evapEnthalpy = heat of vaporization rho1 = liquid density STEP 3: Solve alpha1 equation using MULES with source terms prescribed as Code:
Su = mDot/rho2; Sp = 0.0; STEP 5: Repeat STEP 1 Please kindly review and tell me where this is wrong. Suggestions on more correct implementation of the source terms for evaporation would be well appreciated. Thanks for the help. 

October 4, 2010, 03:21 

#2  
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Sabin Ceuca
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Hi Ovie,
I am also struggling to implement temperature driven phase change. I tried the same as you did but my Su=mDot/rhoLiquid=HTC_liquid/rhoLiquid*(TsatT)/(latentHeat)*InterfacialAreaDensity. My Source term looks different because my phase change is due to condensation. My problems are that it crashes and I don’t get any reasonable results. What do you mean by ? Quote:
Sabin 

October 4, 2010, 03:44 

#3  
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Ovie Doro
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Hi Sabin,
Quote:
In the case of Bitan Shu's model, the simulation reports completely strange results. I really dont know where to start from at the moment. I am reading up another paper by P. Keller et al. (Numerical Simulation of Evaporating Droplets with Chemical Reactions using a Volume of FLuid Method) where they used interFoam and reported nice results. I think I might get some practical details on the implementation from there. Thanks.. 

October 4, 2010, 04:29 

#4 
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Sebastian Gatzka
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As far as I know Shu used OpenFOAM in his Ph.D. thesis.
I'm sure you can get more informations out of if that of the paper. Try to get it!
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October 4, 2010, 17:21 

#5  
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Ovie Doro
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Hi Sega
Quote:
Thanks 

October 4, 2010, 18:35 

#6  
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Sebastian Gatzka
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Quote:
Please contact him directly: http://www.tecies.com/
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October 4, 2010, 18:40 

#7  
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Ovie Doro
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Quote:
Thanks... 

October 4, 2010, 18:46 

#8  
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Sebastian Gatzka
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Quote:
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October 4, 2010, 18:48 

#9 
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Ovie Doro
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Very well then.
Thanks for the help. 

October 6, 2010, 05:54 

#10 
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Nima Samkhaniani
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hi ovie
could you implement shu paper properly ? i tried it, i have used interPhaseChangeFoam , but my results can't follow interface exactly,please inform me about ur last effort!!!!! and i suggest you look at interPhaseChangeFoam and MULE code in it !!!! 

December 16, 2011, 08:02 

#11 
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Lars Kiewidt
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Ovie, by the way, I found that my results depend on the timestep. The larger the timestep, the more liquid is evaporating.


December 16, 2011, 08:10 

#12 
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Ovie Doro
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Well that comes down to your grid sizes and the size of your CFL number. In my case I used a well resolved grid (try the grid sizes specified in Wondra's paper) and specified variable time step in controlDict. The results were very comparable to those reported in Wondra's paper.


December 16, 2011, 10:44 

#13  
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Nima Samkhaniani
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Quote:
http://www.cfdonline.com/Forums/blogs/nimasam/906boilingopenfoam.html and here http://www.cfdonline.com/Forums/ope...hangefoam.html 

August 31, 2018, 07:36 
multiphase vapourisation

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Thomas Flint
Join Date: Jan 2016
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Hi,
I know I'm a little late to this thread but I'm hoping you are all still active in this field. I'm trying to implement a multiphase evaporation and diffusion model. Basically I have selected metallic phases and an atmospheric phase. e.g. Fe, Fevapour, Ni, Nivapour, Pb, Pbvapour, air. I would like to implement phase change between the selected phases as m_dot/rho. I have been modifying the multiphaseeulerfoam solver for this application. I have already implemented the diffusion between selected phase pairs in the solveAlphas function, however the selected phase transformation is proving difficult. I'd really appreciate some pointers. I have found the phase pairs by checking for their names, i.e. if(phase2.name()==(phase1.name()+"vapour")){ mdot=.....; } I dont really know where to go from here to find the source term for MULES. I think the flux contribution is important too but I have no idea what this should be. Any help would be greatly appreciated All the best, Tom 

August 3, 2019, 08:00 
1 Phase Stefan Problem ~ POINT SINK model

#15  
Senior Member

Hello Foamers,
Hope this thread is active. After looking into the source code posted by Ovie Doro, it seems expected equations are upright in front for my work. My topic of research is to build the 1D mathematical model by simulating the coal pyrolysis in OpenFOAM. Initially, for dry coal the prolysis phenomenon is executed based on FireFOAM solver. In case of WET COAL, the moisture need to be evaporated at 100deg by supplying heat from one end of the wall (point sink idealogy)  followed by evaluation of mass and energy balance. I have manipulated the code of Ovie Doro a bit: (below) Quote:
Quote:
So, should the mass and energy balance equations need to be fitted as boundary condition (or) interface condition? How and where the above set of coding can be fitted in OpenFOAM and compiled appropriately ? ENERGY EQU: rho*Cp*(delT/delt) = del/delx[K*delT/delx ] + r*cp*delT/delx + rho*delQ/delT (W/m3) REF  Clear details here in this MANUSCRIPT ~ http://scihub.tw/https://doi.org/10...361(83)902259 Images attached with schematic model and curve. I am in need of some ideas or assistance to implement my work. Thank you 

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