Hydraulic radius in Manning's formula Calculator

✖Cross-Sectional Area is the area of a two-dimensional shape that is obtained when a three-dimensional shape is sliced perpendicular to some specified axis at a point.ⓘ Cross-Sectional Area [A]			+10% -10%
✖Wetted Perimeter is the length of the interface between a flowing fluid (such as water in a river or stream) and the channel or bed through which it is flowing.ⓘ Wetted Perimeter [P]			+10% -10%

✖Hydraulic Radius 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 in Manning's formula [r_H]

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Hydraulic radius in Manning's formula

Formula

`"r"_{"H"} = "A"/"P"`

Example

`"0.15m"="12.0m²"/"80m"`

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Hydraulic radius in Manning's formula Solution

STEP 0: Pre-Calculation Summary

Formula Used

Hydraulic Radius = Cross-Sectional Area/Wetted Perimeter
r_H = A/P
This formula uses 3 Variables

Variables Used

Hydraulic Radius - (Measured in Meter) - Hydraulic Radius 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.
Cross-Sectional Area - (Measured in Square Meter) - Cross-Sectional Area is the area of a two-dimensional shape that is obtained when a three-dimensional shape is sliced perpendicular to some specified axis at a point.
Wetted Perimeter - (Measured in Meter) - Wetted Perimeter is the length of the interface between a flowing fluid (such as water in a river or stream) and the channel or bed through which it is flowing.

STEP 1: Convert Input(s) to Base Unit

Cross-Sectional Area: 12 Square Meter --> 12 Square Meter No Conversion Required
Wetted Perimeter: 80 Meter --> 80 Meter No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

r_H = A/P --> 12/80

Evaluating ... ...

r_H = 0.15

STEP 3: Convert Result to Output's Unit

0.15 Meter --> No Conversion Required

FINAL ANSWER

0.15 Meter <-- Hydraulic Radius

(Calculation completed in 00.004 seconds)

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< 4 Manning's Equation Calculators

Manning's Equation

Go Stream Velocity = (1/Manning’s Roughness Coefficient)*(Hydraulic Radius)^(2/3)*(Bed Slope)^(1/2)

Hydraulic Radius using Manning Equation

Go Hydraulic Radius = ((Stream Velocity*Manning’s Roughness Coefficient)/(Bed Slope^(1/2)))^(3/2)

Slope of Gradient of Stream Bed given Discharge in Manning's Equation

Go Bed Slope = ((Stream Velocity*Manning’s Roughness Coefficient)/Hydraulic Radius^(2/3))^2

Hydraulic radius in Manning's formula

Go Hydraulic Radius = Cross-Sectional Area/Wetted Perimeter

Hydraulic radius in Manning's formula Formula

Hydraulic Radius = Cross-Sectional Area/Wetted Perimeter
r_H = A/P

What is Manning's Equation & limitations of Manning's Equation?

Manning's 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.
Some limitations of Manning's Equation include the assumption of steady flow, uniform flow conditions, and the need for accurate estimation of the roughness coefficient. It may not be suitable for complex flow systems with non-uniform flow conditions.

What does a greater Hydraulic Radius indicate & where it is used?

The Hydraulic Radius indicates a channel's flow efficiency. The greater the hydraulic radius, the channel the more volume it can carry.
The hydraulic radius is one of the main properties that control the amount of fluid discharge of a channel and its ability to move sediments. A high hydraulic radius value indicates that the channel contains a lower volume of contact fluid and a greater cross-sectional area.

How to Calculate Hydraulic radius in Manning's formula?

Hydraulic radius in Manning's formula calculator uses Hydraulic Radius = Cross-Sectional Area/Wetted Perimeter to calculate the Hydraulic Radius, The Hydraulic Radius in Manning's Formula is defined as the ratio of the cross-sectional area A of flow to the wetted perimeter P of the channel or pipe. Hydraulic Radius is denoted by r_H symbol.

How to calculate Hydraulic radius in Manning's formula using this online calculator? To use this online calculator for Hydraulic radius in Manning's formula, enter Cross-Sectional Area (A) & Wetted Perimeter (P) and hit the calculate button. Here is how the Hydraulic radius in Manning's formula calculation can be explained with given input values -> 0.15 = 12/80.

FAQ

What is Hydraulic radius in Manning's formula?

The Hydraulic Radius in Manning's Formula is defined as the ratio of the cross-sectional area A of flow to the wetted perimeter P of the channel or pipe and is represented as r_H = A/P or Hydraulic Radius = Cross-Sectional Area/Wetted Perimeter. Cross-Sectional Area is the area of a two-dimensional shape that is obtained when a three-dimensional shape is sliced perpendicular to some specified axis at a point & Wetted Perimeter is the length of the interface between a flowing fluid (such as water in a river or stream) and the channel or bed through which it is flowing.

How to calculate Hydraulic radius in Manning's formula?

The Hydraulic Radius in Manning's Formula is defined as the ratio of the cross-sectional area A of flow to the wetted perimeter P of the channel or pipe is calculated using Hydraulic Radius = Cross-Sectional Area/Wetted Perimeter. To calculate Hydraulic radius in Manning's formula, you need Cross-Sectional Area (A) & Wetted Perimeter (P). With our tool, you need to enter the respective value for Cross-Sectional Area & Wetted Perimeter 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 Hydraulic Radius?

In this formula, Hydraulic Radius uses Cross-Sectional Area & Wetted Perimeter. We can use 1 other way(s) to calculate the same, which is/are as follows -

Hydraulic Radius = ((Stream Velocity*Manning’s Roughness Coefficient)/(Bed Slope^(1/2)))^(3/2)

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