3.5. Average Velocity and Discharge Calculations

Try these first

1. 1.

   What is the formula for calculating average velocity?

   Hint

   Think about flow rate and area.

2. 2.

   What does the Reynolds number indicate?

   Hint

   Consider its threshold values.

3. 3.

   What is the critical Reynolds number for laminar flow?

   • 1000
   • 2000
   • 2500

   Hint

   Consider common thresholds for flow types.

4. 4.

   The average velocity in laminar flow is directly proportional to which of the following?

   • True
   • False

   Hint

   Review relationships between variables.

5. 5.

   A fluid of specific gravity 0.9 and viscosity 0.6 Pa·s flows through a 100mm diameter pipe. Calculate the average velocity if the flow rate is 0.1 m³/s.

   Hint

   You need to derive the area from the diameter first.

6. 6.

   Determine the pressure drop across a 25m length of pipe with viscosity of 0.8 Pa·s and experiencing an average flow velocity of 0.5 m/s, with the diameter given as 50mm.

   Hint

   Look to apply the Darcy-Weisbach equation if familiar.