47.2.3. Critical Velocity Concept

Try these first

1. 1.

   What is critical velocity?

   Hint

   Think about why water flows in a channel.

2. 2.

   What does the depth of flow affect?

   Hint

   Consider the formula that relates depth to velocity.

3. 3.

   What is the formula for critical velocity (Vc)?

   • Vc = 0.55·D^0.64
   • Vc = 0.75·D^0.45
   • Vc = D^0.64

   Hint

   Think about the components in the context of flow.

4. 4.

   True or False: Higher sediment sizes require lower velocities to remain in suspension.

   • True
   • False

   Hint

   Recall the critical velocity ratio concept.

5. 5.

   A channel has a flow depth of 4 meters. Calculate the critical velocity. Discuss the implications of not maintaining this speed.

   Hint

   Apply the formula carefully considering flow depth.

6. 6.

   If the sediment is a mix with a ratio of m = 1.2, what does this indicate about the required critical velocity compared to normal? Provide reasoning.

   Hint

   Relate it back to the original formula and effects of sediment type.