Velocities in patch/yosioka
As discussed with @fjonas & @goeringc on Monday, we wanted to implement the velocities using the formula from Doinikov instead of taking the derivative of the polynomial. However the velocities defined in the lectures are valid only for viscous fluids as far as I understand.
zeta are needed to compute the corresponding coefficients.
What do you think? Maybe we can also discuss this on Monday.