[zhulianhua]

Hi! All,

I'm trying to write a solver to solve the discrete velocity Boltzmann equation (DVBE). This equation describe the evolution of the distribution function $f$.

$f$ is a function of $(t, x, y, z, \xi_x, \xi_y, \xi_z)$, here the $\xi_x, \xi_y, \xi_z$ is the discrete velocity.

So in each CELL, there is discrete velocity grid (DVG, uniform and same for all cells), it defines the velocity grid for $\xi_x, \xi_y, \xi_z$. The $f$ of the Cell is defined on that grid.


Now, the problem is that the unkonwns in each cell is an 3D array to store the distribution functions of the cell.

As far as i googled, the are two possible ways for that, (I guess, totally)
1. Store the f in the physical Mesh as PtrList<volScalarField> F. The list size is the number of the elements in the DVG. In this way, it similar to the species representation in multi-component problem. [link]

2. I saw there is a FieldField class in OF. So I was considering if it is possible to define the distribution function in each cell as a volScalarField, and for the whole physical mesh, define a FieldField object.

Sorry if my problem is not clear.

Best,

Lianhua