If a control volume is considered, across which matter and energy flows.When the motion of particles is considered then the equations used for La-grangian approach are not suitable for solving control volume problems .Where Eulerian approach is convenient to solve control volume problem. But the basic formulae of thermodynamics and mass transfer are derived based on langranian approach. So , it is required to transform all the formulae from Langranian approach to Eulerian approach and Reynolds transportation theorem describes that.
