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XiFoam enthalpy equation in partially premixed case |
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#1 |
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Guilherme Sempionato
Join Date: Aug 2011
Posts: 12
Rep Power: 15 ![]() |
Hi all,
I am researching now the possible XiFoam implementation to a partially pre-mixed combustion case but there are some terms in enthalpy equation that are puzzling me. There is a annotated possible solution in EauEqn.H but I could not encounter a specific paper to detail this solution to a secure implementation. if (ign.ignited()) { volScalarField& heau = thermo.heu(); fvScalarMatrix heauEqn ( fvm::ddt(rho, heau) + mvConvection->fvmDiv(phi, heau) + (fvc::ddt(rho, K) + fvc::div(phi, K))*rho/thermo.rhou() + ( heau.name() == "eau" ? fvc::div ( fvc::absolute(phi/fvc::interpolate(rho), U), p, "div(phiv,p)" )*rho/thermo.rhou() : -dpdt*rho/thermo.rhou() ) - fvm::laplacian(turbulence->alphaEff(), heau) // These terms cannot be used in partially-premixed combustion due to // the resultant inconsistency between ft and heau transport. // A possible solution would be to solve for ftu as well as ft. //- fvm::div(muEff*fvc::grad(b)/(b + 0.001), heau) //+ fvm::Sp(fvc::div(muEff*fvc::grad(b)/(b + 0.001)), heau) == fvOptions(rho, heau) ); fvOptions.constrain(heauEqn); heauEqn.solve(); fvOptions.correct(heau); } The temperature field is presenting some discrepancies in partially premixed cases and I think that is due this terms. Does someone knows more about this commented possible solution? Thanks, Guilherme Sempionato. Last edited by sempionato; May 21, 2015 at 14:18. |
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#2 |
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Naman Jain
Join Date: Sep 2015
Location: India
Posts: 4
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Hi Sempionato,
I am working on XiFoam to analyze the combustion of a lean premixed mixture and saw those lines in the EaEqn.H file. Have you found anything related to it? Eagerly waiting for your reply, Thanks, Naman. |
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#3 |
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Sangmin Kim
Join Date: Aug 2019
Posts: 6
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Who can solve this ????
------------------------------------------------------------------ A possible solution would be to solve for ftu as well as ft. - fvm::div(muEff*fvc::grad(b)/(b + 0.001), heau) + fvm::Sp(fvc::div(muEff*fvc::grad(b)/(b + 0.001)), heau) -------------------------------------------------------------------- <- How to use these terms???? Thanks. -SM- |
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#4 |
New Member
Join Date: Jul 2019
Posts: 1
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Urgent!!! pls
volScalarField Db("Db", turbulence->muEff()); These terms cannot be used in partially-premixed combustion due to - fvm::div((Db*fvc::grad(b))/(b + 0.001)), heau) //+ fvm::Sp(fvc::div((Db*fvc::grad(b)/(b + 0.001))), heau) Did any solve this? I tried to create surfacefield for fvm: ![]() still not working? Are these terms essential for Partially premix case Thanks lom |
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