1.4. Lecture # 58

Try these first

1. 1.

   What is Reynolds shear stress?

   Hint

   Think about how turbulence impacts motion.

2. 2.

   Define the closure problem in CFD.

   Hint

   Focus on modeling in turbulence.

3. 3.

   What does Reynolds shear stress indicate in fluid dynamics?

   • It indicates mean flow velocity.
   • It indicates turbulent fluctuations.
   • It indicates pressure drop.

   Hint

   Think about turbulence's role in fluid flow.

4. 4.

   The closure problem in CFD involves:

   • True
   • False

   Hint

   It relates to simplifying complex behaviors in flow.

5. 5.

   A fluid with a Reynolds number of 10^5 is experiencing high turbulence. Discuss how the Kolmogorov length scale influences the required computational grid size for a DNS simulation.

   Hint

   Remember how the scale ratio between turbulent structures affects simulation design.

6. 6.

   Explain how the principles derived from the k-epsilon model can be applied in practical engineering scenarios like aircraft design.

   Hint

   Consider how energy dynamics dictate aerodynamic efficiency.