For free flow models, we take the number of "physical" equations (e.g. 4 for a 3D NavierStokes problem, 3 velocity components and pressure) and subtract the number of dimensions. This yields the number of equations to be solved on the cell centers. Works also for non-isothermal models.
#include <dumux/discretization/staggered/freeflow/properties.hh>
| Static Public Attributes | |
| static constexpr int | value = numEq - dim | 
| 
 | staticconstexpr |