Question

Which of the three predominant equations for friction loss in fluid flow can be used only for water and is primarily used for open-channel (gravity) flow?

A. Darcy-Weisbach
B. Manning
C. Hazen-Williams
D. All of the above

Answer 1

B. Manning

Step-by-step explanation:

The Manning formula is an empirical formula for velocity estimation of a liquid flowing in a open channel, only used for water. The Manning formula is:

`V = (k)/(n) \cdot R_(h)^(2/3)\cdot S^(1/2)`

Where:

`V` - Cross sectional average velocity, measured in meters per second.

`k` - Conversion factor, dimensionless. (
`k = 1` for SI units)

`n` - Gauckler-Manning constant, measured in
`(s)/(m^(1/3))`.

`R_(h)` - Hydraulic radius, measured in meters.

`S` - Slope of the hydraulic grade line, dimensionless.

Both Darcy-Weisbach and Hazen-Williams formulas are used only for fluid flowing in pipes.

In a nutshell, the correct answer is B.