so it is relatively straightforward

so it is relatively straightforward to compute the dynamic response of the elements. In an Eulerian representation the grid remains fixed and the identity of individual fluid elements is not maintained. Nevertheless, it is customary to view the fluid in an Eulerian mesh cell as a fluid element on which body and surface force may be computed, in a manner competely analogous to a Lagrangian calculation. The two methods differ, however, in the manner in which the fluid elements are moved to nex positions after their new velocities have been computed. In the Lagrangian case the grid simply moves with the computed element velocities