4.1.7. Euler and Lagrange

4.1.7.1. What is the difference between the Euler and Lagrange approach?

  • Lagrange:
    • Moving frame of reference
    • Elements are matter
    • Results in pathlines
  • Euler:
    • Stationary frame of reference
    • Elements are spatial
    • Results in streamlines

4.1.7.2. What are the advantages and disadvantages between the Euler and Lagrange approach?

  • Lagrange:
    • Advantage: More suitable than Euler for the dynamics of discrete particles in a fluid e.g. flow visualisation.
    • Disadvantage: Computationally expensive to keep track of large numbers of particles in a flow field
  • Euler:
    • Advantage: More suitable than Lagrange for the dynamics of a fluid flow field, e.g. CFD
    • Disadvantage: Time step limited by grid due to stability or accuracy