hey
i am currently trying to model an equation using comsol - it is a transport equation, i need some help with how best to put it into the standard forms.
it is a water transport equation that accounts for drag within a fuel cell.
the calculation of a is required by iteration of the equation between two points which are initially known, but will increase as water accumulates in the cell.
i have used the convective diffusion equation - but am stuck as i do not know how to progress any further, i will attach my best attempt in an MPH file