[blue_arrow98]

Hey guys, I am actually working on developing a turbulence model for magneto hydrodynamic flow. I need to modify a coefficient (which is dimensionedScalar) used in the model. In the original model, it has a constant number value, but in my case I need it to be a function of ratio of Hartmann number to Reynold's number (Ha/Re), but it should be still a dimensioned Scalar.

Now while defining the ratio, Ha/Re = sigma*(B)^2/(U)^2*rho.

Now here, B is magnetic field and U is Velocity (both of which are volVectorField). How do I perform this operation so that my LHS and RHS become of same type. I tried a lot, but I always end up with "error: no match for operator="

Any suggestions are more than welcome!