Section Factor Calculation for Rectangular Channel

The section factor for a flow in a rectangular channel carrying discharge can be calculated using the following formula:

Z = (B + 2y) y

where Z is the section factor, B is the width of the channel, and y is the depth of flow.

Calculation of Section Factor

Given:

Discharge (Q) = 3 cumec

Bed slope (S) = 1 in 1600

Roughness coefficient (n) = 0.02

To calculate the section factor, we first need to determine the depth of flow (y). The Manning's equation can be used for this purpose:

Q = (1/n) A R^(2/3) S^(1/2)

where A is the cross-sectional area of flow, R is the hydraulic radius of flow, and S is the bed slope.

For a rectangular channel, A = By and R = y/2. Substituting these values in the Manning's equation and solving for y, we get:

y = (Qn^2/[(B + 2yn)^(2/3) S^(1/2)])^(3/8)

Next, we can use the value of y to calculate the section factor using the formula mentioned above.

Once the section factor is calculated, it can be used to determine the velocity of flow and other hydraulic parameters of interest.

Conclusion

In conclusion, the section factor for a flow in a rectangular channel carrying a discharge of 3 cumec can be calculated using the Manning's equation and the formula for section factor. The calculation involves determining the depth of flow and using it to calculate the section factor. The section factor is an important hydraulic parameter that can be used to determine the velocity of flow and other parameters of interest.