2. LES Methodology

Try these first

1. 1.

   What does LES stand for?

   Hint

   Think of the term that directly refers to larger vortices.

2. 2.

   What is the primary benefit of using LES over DNS?

   Hint

   Consider the trade-off between accuracy and resource use.

3. 3.

   What is the main purpose of Large Eddy Simulation?

   • To resolve all turbulence scales
   • To model the behavior of large eddies
   • To simulate laminar flow

   Hint

   Think about which aspect of fluid dynamics LES focuses on.

4. 4.

   True or False: The Kolmogorov hypothesis applies to both large and small eddies.

   • True
   • False

   Hint

   Recall what the hypothesis states about the behavior of small eddies.

5. 5.

   In a specific case study of a turbulent jet, describe how you would implement LES. What factors would you consider in your filtering approach?

   Hint

   Think about the relationship between grid size and the scales of turbulence.

6. 6.

   Evaluate a scenario where a universal turbulence model fails. What does this imply about the behavior of larger eddies?

   Hint

   Reflect on the characteristics of large eddies compared to small ones.