
[Sponsors] 
February 22, 2011, 07:44 

#21 
Senior Member
Anton Kidess
Join Date: May 2009
Location: Germany
Posts: 1,377
Rep Power: 29 
It means that you are trying to solve for two variables within one equation.


February 22, 2011, 07:49 

#22 
Senior Member
Balkrishna Patankar
Join Date: Mar 2009
Location: Pune
Posts: 123
Rep Power: 16 
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 
Member
Rohith
Join Date: Oct 2012
Location: Germany
Posts: 57
Rep Power: 12 
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: 17
Rep Power: 10 
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: 17
Rep Power: 10 
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: 12 
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 
New Member
Sandip Wadekar
Join Date: Oct 2014
Posts: 17
Rep Power: 10 
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: 17
Rep Power: 10 
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: 13
Rep Power: 9 
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 
Member
Rohith
Join Date: Oct 2012
Location: Germany
Posts: 57
Rep Power: 12 
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: 13
Rep Power: 9 
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 
Thread Tools  Search this Thread 
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Problem with zeroGradient wall BC for temperature  Total temperature loss  cboss  OpenFOAM  12  October 1, 2018 06:36 
Calculation of the Governing Equations  Mihail  CFX  7  September 7, 2014 06:27 
monitoring point of total temperature  rogbrito  FLUENT  0  June 21, 2009 17:31 
udf for varying inlet temperature  aravind  FLUENT  0  October 27, 2008 10:08 
chemical reaction  decompostition  La S. Hyuck  CFX  1  May 23, 2001 00:07 