2. Introduction to Open Channel Flow and Uniform Flow (Contnd.)

Try these first

1. 1.

   What is Manning's equation used for?

   Hint

   Consider factors like hydraulic radius.

2. 2.

   What does the hydraulic radius represent?

   Hint

   Think about how area and perimeter are related.

3. 3.

   What is the formula for calculating hydraulic radius?

   Hint

   Think about the relationship between area and perimeter.

4. 4.

   Manning's 'n' value is influenced by what?

   • Channel slope
   • Channel width
   • Surface roughness

   Hint

   Consider what causes friction in a flowing stream.

5. 5.

   Given a wide rectangular channel with a width of 10 meters and a depth of 3 meters, determine the flow rate using Manning's equation if the channel is lined with smooth concrete (n = 0.012) and the slope is 0.001.

   Hint

   Calculate the area and perimeter before plugging into Manning's equation.

6. 6.

   A trapezoidal channel has a bottom width of 5m, side slopes of 2:1, and a depth of 2 meters. Calculate its Manning's roughness and how it impacts flow when the bottom opens up to flood plains with an 'n' of 0.030.

   Hint

   Use geometric properties to ascertain area and perimeter before estimating 'Q'.