The boundary condition in FreeFem

[weixj (Xiaojing Wei)]

Now, I need to solve the MHD system with the following condition

But I don’t know how this boundary condition is represented in the code

This is the equations

[fb77 (François Bouchut)]

You can look at

The boundary condition of Hall-MHD model

Hello, everyone. Now I’m using freefem++ to solve the incompressible hall-MHD equations, but I’ve encountered a problem regarding the boundary conditions of the magnetic field. \mu\nabla\times (\nabla\times\mathbf{B})+(\mathbf{u}^n\cdot\nabla)\mathbf{B}^n-(\mathbf{B}^n\cdot\nabla)\mathbf{u}^n+\eta\nabla\times\left((\nabla\times\mathbf{B}^n)\times\mathbf{B}^n\right)=\mathbf{g} \nabla\cdot\mathbf{B}=0 Before solving, assume that the velocity field \mathbf{u}^n,\mathbf{B}^n is already known (I …