2.7. Production of Turbulent Kinetic Energy

Try these first

1. 1.

   What is turbulent kinetic energy?

   Hint

   Think about both average and fluctuating components in a turbulent environment.

2. 2.

   Define Reynolds shear stress.

   Hint

   Consider how shear affects average flow in a turbulent medium.

3. 3.

   What does turbulent kinetic energy (TKE) measure?

   • Mean energy only
   • Fluctuating energy only
   • Both mean and fluctuating energy

   Hint

   Recall that TKE includes both average and fluctuating aspects.

4. 4.

   True or False: The closure problem is trivial in turbulence modeling.

   • True
   • False

   Hint

   Think about what aspects of turbulence require more detailed modeling.

5. 5.

   Calculate the amount of turbulent kinetic energy when given a flow velocity of 30 m/s and significant fluctuations at 2 m/s.

   Hint

   Remember the TKE formula involves both the mean flow velocities and the fluctuations.

6. 6.

   Explain why DNS might not be feasible for all engineering applications despite its accuracy. What might you propose as a solution?

   Hint

   Think about the available technology and the complexity of calculating turbulent flows.