22.4.2. Roughness Effects in Pipe Flow

Try these first

1. 1.

   Explain what surface roughness is in fluid flow.

   Hint

   Think about how surfaces can vary in texture.

2. 2.

   What is the formula for hydraulic diameter?

   Hint

   Remember the components of hydraulic diameter.

3. 3.

   What determines whether the flow is laminar or turbulent?

   • Pressure
   • Reynolds number
   • Viscosity
   • Temperature

   Hint

   This number provides insight into the flow characteristics.

4. 4.

   True or False: Roughness only affects laminar flow.

   • True
   • False

   Hint

   Consider how flow changes with texture.

5. 5.

   A pipe has a diameter of 0.5 m and a roughness height of 0.01 m. Calculate the friction factor for turbulent flow using entries from Moody's diagram.

   Hint

   Consider the flow implications at this scale.

6. 6.

   A square duct of side length 1 m has a flow of water with a Reynolds number of 5000. Determine whether the flow is laminar or turbulent and calculate the hydraulic diameter.

   Hint

   Refer to the critical Reynolds number to classify flow type.