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February 22, 2011, 08:44 

#21 
Senior Member
Anton Kidess
Join Date: May 2009
Location: Germany
Posts: 1,241
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It means that you are trying to solve for two variables within one equation.


February 22, 2011, 08:49 

#22 
Senior Member
Balkrishna Patankar
Join Date: Mar 2009
Location: Pune
Posts: 123
Rep Power: 10 
Thanks. That is clear . However a formulation like below ,
Code:
fvScalarMatrix hEqn ( fvm::ddt(rho, h) + fvm::div(phi, h)  fvm::laplacian(turbulence>alphaEff(), h) == DpDt ); 

July 18, 2013, 05:12 

#23 
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Rohith
Join Date: Oct 2012
Location: Germany
Posts: 57
Rep Power: 6 
Hi BalKrishna
Have you found the solution for this problem. How can some body solve 2 variables here. Regards Rohith 

June 16, 2015, 10:10 

#24 
New Member
Sandip Wadekar
Join Date: Oct 2014
Posts: 12
Rep Power: 4 
Dear sir,
I am getting the error after using Foam::tanh(...) The error is: call of overloaded ‘tanh(const int&)’ is ambiguous c[ignCell] =1Foam::tanh(ignSite.cells()[icelli]); The code is: forAll(ign.sites(), i) { const ignitionSite& ignSite = ign.sites()[i]; if (ignSite.igniting()) { forAll(ignSite.cells(), icelli) { label ignCell = ignSite.cells()[icelli]; c[ignCell] =1Foam::tanh(ignSite.cells()[icelli]); } } } 

June 16, 2015, 10:18 

#25 
New Member
Sandip Wadekar
Join Date: Oct 2014
Posts: 12
Rep Power: 4 
Dear sir,
I am getting the error after using Foam::tanh(...) The error is: call of overloaded ‘tanh(const int&)’ is ambiguous c[ignCell] =1Foam::tanh(ignSite.cells()[icelli]); The code is: forAll(ign.sites(), i) { const ignitionSite& ignSite = ign.sites()[i]; if (ignSite.igniting()) { forAll(ignSite.cells(), icelli) { label ignCell = ignSite.cells()[icelli]; c[ignCell] =1Foam::tanh(ignSite.cells()[icelli]); } } } 

June 16, 2015, 10:41 

#26 
Member
Rohith
Join Date: Oct 2012
Location: Germany
Posts: 57
Rep Power: 6 
Hi Sandip,
I hope tanh in openfoam takes only a value i.e if you define a dimensionedScalar then please define its value. See that there exists no Fields. I See Ignsites is a constant, i am not sure. If you can define it so. Best Regards, Rohith 

June 16, 2015, 11:09 

#27 
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Sandip Wadekar
Join Date: Oct 2014
Posts: 12
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Thanks Raghavendra
I have tried with the interger value 5, but still i am getting the same error: call of overloaded ‘tanh(int)’ is ambiguous c[ignCell] =Foam::tanh(5); 

June 18, 2015, 03:32 

#28 
New Member
Sandip Wadekar
Join Date: Oct 2014
Posts: 12
Rep Power: 4 
Hello friends,
I am compile the below mention code and i am getting the error error: ‘distance’ was not declared in this scope c = Foam::tanh[distance]; Code:
pointField meshPoints(mesh.points()); label i(0); forAll( meshPoints, kk) { vector curPoint = meshPoints[kk]; vector distance = curPoint  vector(0, 0, 0); i++; scalar dis = mag(distance); Info<< "distance = " << dis << endl; } Info << i << " Points are changed" << endl; volScalarField c = Foam::tanh[distance]; 

June 30, 2016, 17:32 

#29  
New Member
elham usefi
Join Date: Apr 2016
Location: tabriz,iran
Posts: 12
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Quote:
Hi i knw this post is old but i need help on this problem in my case Cp varies in different locations, so I need to write energy equation with enthalpy. I wrote it like this: Code:
fvScalarMatrix EEqn ( fvm::div(phi, E)  fvm::laplacian(k_n/cp, E) == fvOptions(rho,E) ); EEqn.relax(); fvOptions.constrain(EEqn); EEqn.solve(); fvOptions.correct(E); T=E/cp; rhok = (1.0  beta*(T  TRef)); can u help me? 

July 1, 2016, 01:09 

#30 
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Rohith
Join Date: Oct 2012
Location: Germany
Posts: 57
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Hi,
The only error i see is that you have defined enthalpy as E=cp*T But it is deltaE = cp*deltaT. Hope it helps Regards, Rohith 

July 3, 2016, 18:12 

#31  
New Member
elham usefi
Join Date: Apr 2016
Location: tabriz,iran
Posts: 12
Rep Power: 3 
Quote:
thank u for ur response but I didnt get it! if we replace E with cp*T in Code:
( fvm::div(phi, E)  fvm::laplacian(k_n/cp, E) == fvOptions(rho,E) ); Code:
( fvm::div(phiCp, T)  fvm::laplacian(k_n, T) == fvOptions(rhoCp,T) ); actually first I tried TEqn like this: Code:
( fvm::div(phiCp, T)  fvm::laplacian(k_n, T) == fvOptions(rhoCp,T) ); but when I assume that cp is constant! like this: Code:
( cp*fvm::div(phi, T)  fvm::laplacian(k_n, T) == fvOptions(rhoCp,T) ); so I tried EEqn 

Tags 
density, property, specific heat, temperature 
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