Similar expressions can be obtained for the other directions, for examples,
Net rate of accumulation of mass in CV
Therefore,
The significance of this expression is the same as that for the total mass-conservation rule applied to a CV in the earlier lecture
Re-arrange:
This is the vector-form of continuity-equation and readily applied for all co-ordinate systems. In this course we will focus mostly on Cartesian and cylindrical 1D or 2D geometry. To this end, the above conservation equation may also be written as:
