25.4.3. Coefficients of Discharge

Try these first

1. 1.

   Define the hydraulic gradient line.

   Hint

   Consider the relationship to the liquid's free surface.

2. 2.

   What does a pump do in a fluid system?

   Hint

   Think about the fluid motion and energy transfer.

3. 3.

   What does the hydraulic gradient line represent in open channel flow?

   • Pressure head
   • Free surface
   • Velocity head

   Hint

   Think about where the water surface aligns.

4. 4.

   True or False: A pump decreases mechanical energy of the fluid.

   • True
   • False

   Hint

   Consider the role of pumps in energy transitions.

5. 5.

   A closed tank with a diameter of 3 m has a pipe outlet of diameter 0.2 m. If the water level is 5 m high, calculate the discharge through the pipe using the coefficient of discharge of 0.8.

   Hint

   Calculate the area for the smaller pipe first and then apply the correct formula.

6. 6.

   In a water supply system, the efficiency of a pump is seen to decline from 85% to 75% as flow rates increase. How does this affect the overall system pressure?

   Hint

   Think about how energy loss correlates to system performance - higher losses mean lower pressure delivery.