4.1. Laminar and turbulent flow (Contd.)

Try these first

1. 1.

   What happens to the velocity at the wall in turbulent flow?

   Hint

   Consider the boundary condition at the wall.

2. 2.

   Define turbulent flow in one sentence.

   Hint

   Think about how it compares to laminar flow.

3. 3.

   What is the velocity at the wall in turbulent flow?

   • True
   • False

   Hint

   Think about real-world applications near pipe walls.

4. 4.

   The logarithmic profile is suitable for all types of surfaces.

   • True
   • False
   • Only rough surfaces

   Hint

   Consider where this profile is derived from.

5. 5.

   A pipe's diameter is 15 cm. The velocity at 3 cm from the wall is found to be 50% greater than at 1 cm. Calculate the roughness coefficient k.

   Hint

   Set up comparative equations and remember to account for flow interactions.

6. 6.

   Another rough pipe has velocity readings of 10 m/s at 2 cm and 14 m/s at 5 cm from the wall. Derive the k value for engineering applications.

   Hint

   Utilize percentage increases effectively in your final equations.