14.4.4. Energy Gradient Lines

Try these first

1. 1.

   Define open channel flow.

   Hint

   Think about rivers or channels without a cover.

2. 2.

   What is the hydraulic radius?

   Hint

   Recall the formula A/P.

3. 3.

   What is the primary difference between open channel flow and pipe flow?

   • Open channels have pressure force
   • while pipes do not
   • Pipes have free surfaces
   • while open channels do not
   • Open channels have free surfaces
   • while pipes have pressure forces

   Hint

   Think about what constitutes each type of flow.

4. 4.

   True or False: The hydraulic gradient line in open channel flow is equivalent to the free surface.

   • True
   • False

   Hint

   Consider what happens at the free surface level.

5. 5.

   Design a channel that allows for uniform flow. Calculate the dimensions required to maintain a constant depth of 2m with a width of 8m.

   Hint

   Make sure to analyze forces acting to achieve uniform flow.

6. 6.

   A river experiences rapid changes due to a rainstorm. Describe the energy gradient line behavior during this transition.

   Hint

   Think about how energy redistributes when flow characteristics change quickly.