13.3.1. Mass Conservation

Try these first

1. 1.

   What is mass conservation?

   Hint

   Think about how flow behaves in systems.

2. 2.

   Define displacement thickness.

   Hint

   Consider how boundary layers affect flow.

3. 3.

   What does mass conservation imply in fluid mechanics?

   • Mass can be created
   • Mass cannot be created or destroyed
   • Mass can be destroyed

   Hint

   Think about what happens at any point in a fluid.

4. 4.

   True or False: The velocity at a boundary layer ideally becomes equal to the free stream velocity.

   • True
   • False

   Hint

   Consider how velocity changes near a wall in fluid flow.

5. 5.

   A wind tunnel test shows an airflow with a known velocity profile. How do you find the displacement thickness?

   Hint

   Use boundary conditions to set up your integral.

6. 6.

   Given a Reynolds number of 120,000, how would you classify the flow in a boundary layer?

   Hint

   Define the thresholds for laminar and turbulent flows.