CFD Online Discussion Forums - verification of combustion model: rhoReactingFoam

Hello Foamer's

As a part of our project we have to simulate combustion in a section of an axial turbine combustor. The model we chose to simulate is rhoReactingFoam with intermediate steps for the formation of CO2 via CO.

The version we implemented this project is in 2.1.1 due to the requirements of our university.

Only a 5 degree section of the combustor is created and the side walls are applied wedgeMesh with cyclic boundary conditions.

The fuel enters from a very small block which could be observed as a region of fine mesh in the blockmesh.

All the patches can be seen in paraview by toggeling on the patchnames, block numbers etc by typing in the terminal paraFoam -block , once the blockMesh is created.

However we are running into issues and are getting very high temperatures in the domain when combustion is happening. This unphysical temperatures can be due to solvers not being chosen correctly or may be because of the mesh, but as of now the mesh generated using blockMesh seems good and checkMesh also gives no error.

"Janaf thermo limit exceeds T=5000".

The fv schemes looks like below:

Code:

ddtSchemes

{

    //default         Euler;

    default         SLTS phi rho 0.7; //for quicker convergence

}



gradSchemes

{

    //default         Gauss linear;

    default         cellLimited Gauss linear 1;

}



divSchemes

{

    //default         none;

    default            Gauss linearUpwind Gauss;

    

    div(phi,Yi_h) Gauss multivariateSelection

    {

    hs    linearUpwind Gauss;

    

    O2    linearUpwind Gauss;

    H2O    linearUpwind Gauss;

    CH4    linearUpwind Gauss;

    CO    linearUpwind Gauss;

    CO2    linearUpwind Gauss;

    N2    linearUpwind Gauss;

    };

    

    div((muEff*dev2(T(grad(U))))) Gauss linear;

}



laplacianSchemes

{

    default         Gauss linear uncorrected;

    //default         Gauss linear corrected;

}



interpolationSchemes

{

    default         linear;

}



snGradSchemes

{

    default         uncorrected;

    //default         corrected;

}



fluxRequired

{

    default         no;

    p;

}

As can be seen, most of the solvers are linear. I am not entirely sure if we need to change this to some other solver

The archive is on github in the following link

We will be glad to receive feedbacks and improvement suggestions.

Thank you in advance