A 2.1-m wide rectangular channel with a bed slope of 0.043 has a depth of flow of 9.29 in m. Manning's roughness coefficient is 0.015. Determine the steady uniform discharge in the channel (cms).

Principles of Geotechnical Engineering (MindTap Course List)
9th Edition
ISBN:9781305970939
Author:Braja M. Das, Khaled Sobhan
Publisher:Braja M. Das, Khaled Sobhan
Chapter8: Seepage
Section: Chapter Questions
Problem 8.11P
icon
Related questions
Question

Can you please show how to do this problem? I’m confused on this homework question and please box answer and pleas write clear thank you.

### Problem Statement

A 2.1-m wide rectangular channel with a bed slope of 0.043 has a depth of flow of 9.29 m. Manning's roughness coefficient is 0.015. Determine the steady uniform discharge in the channel (cms).

### Solution Steps

To calculate the steady uniform discharge in the channel, we use Manning's equation:

\[ Q = \frac{1}{n} A R^{2/3} S^{1/2} \]

where
- \( Q \) is the discharge (cubic meters per second, cms)
- \( n \) is Manning's roughness coefficient
- \( A \) is the cross-sectional area of flow (square meters)
- \( R \) is the hydraulic radius (meters)
- \( S \) is the slope of the channel bed

#### Step-by-Step Calculation:

1. **Calculate the cross-sectional area (A):**
   For a rectangular channel,
   \[ A = b \cdot h \]
   where \( b \) is the width of the channel and \( h \) is the depth of flow.
   \[ A = 2.1 \, \text{m} \times 9.29 \, \text{m} = 19.509 \, \text{m}^2 \]

2. **Calculate the wetted perimeter (P):**
   For a rectangular channel,
   \[ P = b + 2h \]
   \[ P = 2.1 \, \text{m} + 2 \times 9.29 \, \text{m} = 20.68 \, \text{m} \]

3. **Calculate the hydraulic radius (R):**
   \[ R = \frac{A}{P} \]
   \[ R = \frac{19.509 \, \text{m}^2}{20.68 \, \text{m}} = 0.943 \, \text{m} \]

4. **Apply Manning's equation:**
   \[ Q = \frac{1}{0.015} \times 19.509 \, \text{m}^2 \times (0.943 \, \text{m})^{2/3} \times (0.043)^{1/2} \]

5. **Perform the calculations:
Transcribed Image Text:### Problem Statement A 2.1-m wide rectangular channel with a bed slope of 0.043 has a depth of flow of 9.29 m. Manning's roughness coefficient is 0.015. Determine the steady uniform discharge in the channel (cms). ### Solution Steps To calculate the steady uniform discharge in the channel, we use Manning's equation: \[ Q = \frac{1}{n} A R^{2/3} S^{1/2} \] where - \( Q \) is the discharge (cubic meters per second, cms) - \( n \) is Manning's roughness coefficient - \( A \) is the cross-sectional area of flow (square meters) - \( R \) is the hydraulic radius (meters) - \( S \) is the slope of the channel bed #### Step-by-Step Calculation: 1. **Calculate the cross-sectional area (A):** For a rectangular channel, \[ A = b \cdot h \] where \( b \) is the width of the channel and \( h \) is the depth of flow. \[ A = 2.1 \, \text{m} \times 9.29 \, \text{m} = 19.509 \, \text{m}^2 \] 2. **Calculate the wetted perimeter (P):** For a rectangular channel, \[ P = b + 2h \] \[ P = 2.1 \, \text{m} + 2 \times 9.29 \, \text{m} = 20.68 \, \text{m} \] 3. **Calculate the hydraulic radius (R):** \[ R = \frac{A}{P} \] \[ R = \frac{19.509 \, \text{m}^2}{20.68 \, \text{m}} = 0.943 \, \text{m} \] 4. **Apply Manning's equation:** \[ Q = \frac{1}{0.015} \times 19.509 \, \text{m}^2 \times (0.943 \, \text{m})^{2/3} \times (0.043)^{1/2} \] 5. **Perform the calculations:
Expert Solution
steps

Step by step

Solved in 3 steps with 2 images

Blurred answer
Knowledge Booster
Highway drainage
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Principles of Geotechnical Engineering (MindTap C…
Principles of Geotechnical Engineering (MindTap C…
Civil Engineering
ISBN:
9781305970939
Author:
Braja M. Das, Khaled Sobhan
Publisher:
Cengage Learning
Fundamentals of Geotechnical Engineering (MindTap…
Fundamentals of Geotechnical Engineering (MindTap…
Civil Engineering
ISBN:
9781305635180
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
Principles of Foundation Engineering (MindTap Cou…
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
Principles of Foundation Engineering (MindTap Cou…
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781305081550
Author:
Braja M. Das
Publisher:
Cengage Learning
Traffic and Highway Engineering
Traffic and Highway Engineering
Civil Engineering
ISBN:
9781305156241
Author:
Garber, Nicholas J.
Publisher:
Cengage Learning
Sustainable Energy
Sustainable Energy
Civil Engineering
ISBN:
9781337551663
Author:
DUNLAP, Richard A.
Publisher:
Cengage,