3.6. Energy Considerations and Flow Regimes

Try these first

1. 1.

   Define specific energy.

   Hint

   Refer to the formula involving height and velocity.

2. 2.

   What characterizes subcritical flow?

   Hint

   Think about flow speed in quiet channels.

3. 3.

   What is specific energy?

   • Potential energy only
   • Total energy per unit weight
   • Kinetic energy only

   Hint

   Think about the formula connecting depth and velocity.

4. 4.

   True or False: In subcritical flow, the specific energy is low.

   • True
   • False

   Hint

   Look back at the definitions of flow states.

5. 5.

   Calculate the total energy for a channel with a uniform depth of 4 ft and velocity of 5 ft/s under gravitational acceleration of 32.2 ft/s².

   Hint

   Plug in depth and velocity correctly into the specific energy formula.

6. 6.

   Design a minim-sized channel with a width of 2 ft that can sustain a flow rate of 10 ft²/s and calculate its downstream conditions.

   Hint

   Use q = A * v for flow calculations, A being width times depth.