Hi Yuri,

Jurjen again. I have downloaded the file and now I'm reading the explanation.
 
I see that the function works as follows:

Parameters
     DEsys   -  a set  of  (linear or non-linear) ODEs or PDEs of any order potentially solvable for highest derivatives for dependent variables with respect to "selected" by initial conditions independent variable "
                                      t
". The number of equations must be equal to the number of dependent variables.

    vars   -  a set of indeterminate functions (all indeterminate functions must have identical arguments) or their names, representing the unknowns of the DE problem.

     ICs     - initial conditions of the form u(a,x,...,z)=b, D[1](u)(a,x,...,z)=d, ..., where {b, ..., d} are any functions with respect to the independent variables (x,...,z). Derivatives in the initial conditions ICs must be specified in indexed D notation (for example, for u(t,x), D[1](u)(a,x) describes the normal derivative on the hyperplane t=a). At least one of ICs must be given to specify the initial hyperplane, as t=a in example above. In the case when the problem requires more  initial conditions than are given then the procedure fills up missing data by some (arbitrary) functions. In the case when are given more ICs than the problem requires then superfluous of them are ignored.

My question now is where to put the boundary conditions? Can they be used as IC's?

The boundary condition at r=R is very important for this problem.

Thanks again for your answer

Hi Yuri

Thank you for your reply. I will try the appointed sheet and test it immediately. Hope it wil work.

What does Cauchy mean in this sense?

best regards

Jurjen

Hi Robert,

Thanks for your reply.

I had indeed found the error of T_Bulk and Cp_Air.

What a pity that the model does not run at your computer as well.

I now tried the numerical solution with the time parameter, but Maple still refuses to calculate. hope to find more replies from your and others.

cheers

jurjen