Lagrangian in a Sentence
  • Two methods are employed in hydrodynamics, called the Eulerian and Lagrangian, although both are due originally to Leonhard Euler.
  • In the Eulerian method the attention is fixed on a particular point of space, and the change is observed there of pressure, density and velocity, which takes place during the motion; but in the Lagrangian method we follow up a particle of fluid and observe how it changes.
  • The Lagrangian method being employed rarely, we shall confine ourselves to the Eulerian treatment.
  • In such cases the boundary condition on the fluid uses the Lagrangian derivative.