On the use of control volumes in continuum mechanics

In this paper the use of control volumes in continuum mechanics is discussed. The global balance equations for momentum and moment of momentum for general control volumes are presented and their equivalence to the balance equations for material bodies is demonstrated. We also consider an approach based on the formulation of a principle of virtual power for control volumes. Based on this principle Lagrange's equations for a control volume are derived. A specialization to so-called rigid control volumes is presented together with a didactic example concerning rocket propulsion. Finally, the balance of energy for a control volume is briefly discussed.