CFD Online Discussion Forums - Seeking explanation why solve zeroes out solution in certain circumstances

I am hoping someone can help me understand the behavior I'm observing with the code at bottom, which I adapted from scalarTransportFoam.C. Since my equation is stating that T isn't changing, I expect the T before the solve to be the same as T after the solve. However, as it is written, the T after the solve is equal to 0 for all m. If I change the construction of DD to

Code:

for (m=0; m<64, ++m)

  {

      DD[m] = scalar(l);

  }

then the code behaves as I'd expect. Namely, T before is equal to T after (=5).

Can anyone explain why solve is setting T to 0 if I use m in the construction of DD? Thanks.

Code:

#include "fvCFD.H"

#include "fvIOoptionList.H"

#include "simpleControl.H"



// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //



int main(int argc, char *argv[])

{

    #include "setRootCase.H"

    #include "createTime.H"

    #include "createMesh.H"

    #include "createFields.H"

    #include "createFvOptions.H"



    simpleControl simple(mesh);



    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //



    Info<< "\nCalculating scalar transport\n" << endl;



    #include "CourantNo.H"



    int m;

    int l = 5;



    scalar DD[64];



    for (m=0; m<64; ++m)

      {

        DD[m] = scalar(m);

      }



    for (m=0; m<64; ++m)

      {

        forAll(U,i)

         {

           T[i] = DD[m];

         }



         Info<<"T Before "<<T[56]<<endl;



         solve

          (

            fvm::ddt(T)

          );

    

        Info<<"T After "<<T[56]<<endl;

      }





    return 0;

}