Question

What is the difference between the “Eulerian” and “Lagrangian” perspectives on fluid motion. It may be helpful to include some mathematical relationships, but also use words.

Answer 1

Eulerian method of description is concerned with the field of flow. In this method variables of flow pattern are computed rather than of a single particle. So if we need pressure in this perspective we will specify pressure at particular points as a variable of time and as the particle will pass through a particular location it will experience the pressure at that point.

In lagrangian method we focus on particular particles. A individual parcel of fluid is followed as it moves through space and time and the variables are specified. So to specify pressure we will take a parcel of fluid and find pressure at every point and time as it moves.