16.6. Specific Energy Curve

Try these first

1. 1.

   Define specific energy in the context of open channel flow.

   Hint

   Think about what contributes to energy in a flowing fluid.

2. 2.

   What does a Froude number less than 1 indicate?

   Hint

   Remember the flow type relative to gravitational forces.

3. 3.

   What does a Froude number greater than 1 signify?

   • Subcritical flow
   • Supercritical flow
   • Critical flow

   Hint

   Think about the relationship with flow speed.

4. 4.

   True or False: Specific energy increases with flow depth for all flow regimes.

   • True
   • False

   Hint

   Look closer at how potential energy is factored.

5. 5.

   A rectangular channel has a width of 4 m and a flow depth of 3 m with a velocity of 5 m/s. Calculate the specific energy and identify the flow regime.

   Hint

   Apply E = y + (v²/2g) for specific energy; use the Froude number formula for flow regime.

6. 6.

   Design a trapezoidal channel with a flow rate of 100 m³/s. What dimensions minimize energy loss while maintaining efficient flow?

   Hint

   Balance between flow area and perimeter; consider the optimal shapes discussed in class.