Manning's Formula for Coefficient of Roughness given Average Velocity Calculator

✖Average Velocity of Uniform Flow is defined as the mean of all different velocities.ⓘ Average Velocity of Uniform Flow [V_avg(U)]			+10% -10%
✖Bed Slope is used to calculate the shear stress at the bed of an open channel containing fluid that is undergoing steady, uniform flow.ⓘ Bed Slope [S]			+10% -10%
✖Hydraulic Radius of Channel is the ratio of the cross-sectional area of a channel or pipe in which a fluid is flowing to the wet perimeter of the conduit.ⓘ Hydraulic Radius of Channel [R_H]			+10% -10%

✖Manning’s Roughness Coefficient represents the roughness or friction applied to the flow by the channel.ⓘ Manning's Formula for Coefficient of Roughness given Average Velocity [n]

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Manning's Formula for Coefficient of Roughness given Average Velocity

Formula

`"n" = (1/"V"_{"avg(U)"})*("S"^(1/2))*("R"_{"H"}^(2/3))`

Example

`"0.034371"=(1/"0.796m/s")*(("0.0004")^(1/2))*(("1.6m")^(2/3))`

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Manning's Formula for Coefficient of Roughness given Average Velocity Solution

STEP 0: Pre-Calculation Summary

Formula Used

Manning’s Roughness Coefficient = (1/Average Velocity of Uniform Flow)*(Bed Slope^(1/2))*(Hydraulic Radius of Channel^(2/3))
n = (1/V_avg(U))*(S^(1/2))*(R_H^(2/3))
This formula uses 4 Variables

Variables Used

Manning’s Roughness Coefficient - Manning’s Roughness Coefficient represents the roughness or friction applied to the flow by the channel.
Average Velocity of Uniform Flow - (Measured in Meter per Second) - Average Velocity of Uniform Flow is defined as the mean of all different velocities.
Bed Slope - Bed Slope is used to calculate the shear stress at the bed of an open channel containing fluid that is undergoing steady, uniform flow.
Hydraulic Radius of Channel - (Measured in Meter) - Hydraulic Radius of Channel is the ratio of the cross-sectional area of a channel or pipe in which a fluid is flowing to the wet perimeter of the conduit.

STEP 1: Convert Input(s) to Base Unit

Average Velocity of Uniform Flow: 0.796 Meter per Second --> 0.796 Meter per Second No Conversion Required
Bed Slope: 0.0004 --> No Conversion Required
Hydraulic Radius of Channel: 1.6 Meter --> 1.6 Meter No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

n = (1/V_avg(U))*(S^(1/2))*(R_H^(2/3)) --> (1/0.796)*(0.0004^(1/2))*(1.6^(2/3))

Evaluating ... ...

n = 0.0343713758125969

STEP 3: Convert Result to Output's Unit

0.0343713758125969 --> No Conversion Required

FINAL ANSWER

0.0343713758125969 ≈ 0.034371 <-- Manning’s Roughness Coefficient

(Calculation completed in 00.007 seconds)

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< 7 Manning's Formula in Uniform Flow Calculators

Manning's Formula for Hydraulic Radius given Average Velocity

Go Hydraulic Radius of Channel = (Average Velocity of Uniform Flow*Manning’s Roughness Coefficient/sqrt(Bed Slope))^(3/2)

Manning's Formula for Coefficient of Roughness given Average Velocity

Go Manning’s Roughness Coefficient = (1/Average Velocity of Uniform Flow)*(Bed Slope^(1/2))*(Hydraulic Radius of Channel^(2/3))

Manning's Formula for Average Velocity

Go Average Velocity of Uniform Flow = (1/Manning’s Roughness Coefficient)*(Hydraulic Radius of Channel^(2/3))*(Bed Slope^(1/2))

Manning's Formula for Slope of Channel Bed given Average Velocity

Go Bed Slope = (Average Velocity of Uniform Flow*Manning’s Roughness Coefficient/(Hydraulic Radius of Channel^(2/3)))^(2)

Manning's Formula for Hydraulic Radius given Chezy's Constant

Go Hydraulic Radius of Channel = (1/Bed Slope)*(Average Velocity of Flow/Chezy's Constant)^2

Manning's Formula for Roughness Coefficient given Chezy's Constant

Go Manning’s Roughness Coefficient = (1/Chezy's Constant)*Hydraulic Depth^(1/6)

Manning's Coefficient using Strickler Formula

Go Manning’s Roughness Coefficient = (Roughness Value^(1/6))/21

Manning's Formula for Coefficient of Roughness given Average Velocity Formula

Manning’s Roughness Coefficient = (1/Average Velocity of Uniform Flow)*(Bed Slope^(1/2))*(Hydraulic Radius of Channel^(2/3))
n = (1/V_avg(U))*(S^(1/2))*(R_H^(2/3))

What is Manning's Equation?

The Mannings equation is an empirical equation that applies to uniform flow in open channels and is a function of the channel velocity, flow area and channel slope. Under the assumption of uniform flow conditions the bottom slope is the same as the slope of the energy grade line and the water surface slope.

How to Calculate Manning's Formula for Coefficient of Roughness given Average Velocity?

Manning's Formula for Coefficient of Roughness given Average Velocity calculator uses Manning’s Roughness Coefficient = (1/Average Velocity of Uniform Flow)*(Bed Slope^(1/2))*(Hydraulic Radius of Channel^(2/3)) to calculate the Manning’s Roughness Coefficient, The Manning's Formula for Coefficient of Roughness given Average Velocity is defined as the roughness factor of the channel for uniform flow in channels. Manning’s Roughness Coefficient is denoted by n symbol.

How to calculate Manning's Formula for Coefficient of Roughness given Average Velocity using this online calculator? To use this online calculator for Manning's Formula for Coefficient of Roughness given Average Velocity, enter Average Velocity of Uniform Flow (V_avg(U)), Bed Slope (S) & Hydraulic Radius of Channel (R_H) and hit the calculate button. Here is how the Manning's Formula for Coefficient of Roughness given Average Velocity calculation can be explained with given input values -> 0.034371 = (1/0.796)*(0.0004^(1/2))*(1.6^(2/3)).

FAQ

What is Manning's Formula for Coefficient of Roughness given Average Velocity?

The Manning's Formula for Coefficient of Roughness given Average Velocity is defined as the roughness factor of the channel for uniform flow in channels and is represented as n = (1/V_avg(U))*(S^(1/2))*(R_H^(2/3)) or Manning’s Roughness Coefficient = (1/Average Velocity of Uniform Flow)*(Bed Slope^(1/2))*(Hydraulic Radius of Channel^(2/3)). Average Velocity of Uniform Flow is defined as the mean of all different velocities, Bed Slope is used to calculate the shear stress at the bed of an open channel containing fluid that is undergoing steady, uniform flow & Hydraulic Radius of Channel is the ratio of the cross-sectional area of a channel or pipe in which a fluid is flowing to the wet perimeter of the conduit.

How to calculate Manning's Formula for Coefficient of Roughness given Average Velocity?

The Manning's Formula for Coefficient of Roughness given Average Velocity is defined as the roughness factor of the channel for uniform flow in channels is calculated using Manning’s Roughness Coefficient = (1/Average Velocity of Uniform Flow)*(Bed Slope^(1/2))*(Hydraulic Radius of Channel^(2/3)). To calculate Manning's Formula for Coefficient of Roughness given Average Velocity, you need Average Velocity of Uniform Flow (V_avg(U)), Bed Slope (S) & Hydraulic Radius of Channel (R_H). With our tool, you need to enter the respective value for Average Velocity of Uniform Flow, Bed Slope & Hydraulic Radius of Channel and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Manning’s Roughness Coefficient?

In this formula, Manning’s Roughness Coefficient uses Average Velocity of Uniform Flow, Bed Slope & Hydraulic Radius of Channel. We can use 2 other way(s) to calculate the same, which is/are as follows -

Manning’s Roughness Coefficient = (1/Chezy's Constant)*Hydraulic Depth^(1/6)
Manning’s Roughness Coefficient = (Roughness Value^(1/6))/21

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