Copy of flow, slope &pipe dia. calculation using manning's formula (2).xls

8/18/2019 Copy of flow, slope &pipe dia. calculation using manning's formula (2).xls

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Manning's formula

v = cross-sectional mean velocity (m/s)

R = hydraulic radius A/P (m)

S = slope of pipe (m/m)

Q= A * 1/n * R 2/3 * S 1/2

V = 1/n * R 2/3 * S 1/2

S = (V * n * R -2/3)2

D = (6.42 *Qn /S 1/2)3/8

Q = volume flow =V*A (m3 /s)

n = Manning coefficient of roughness

A = cross sectional area of flow (m2)P = wetted perimeter (m)


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Calculation

IN!"S #!"!"

Pipe Diameter (inch) ₌ 4

₌ $% ₌ %.%%%%

n ₌ %.%11

V (&t/') ₌ %.%%

slope () ₌ %

₌!"!!#$

P (m)₌

!"$%&'

(m)₌

!"!2%#

Q= A * 1/n * R 2/3 * S 1/2 V = 1/n * R 2/3 * S 1/2

Percent of (or ratio to) full depth ($!! ifflowing full) = (!$!!)

Q (3 /')

A (m2)


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Calculation

IN!"S #!"!"

Pipe Diameter (inch) ₌ 8 S () ₌ %.%%%

₌ %

n ₌ %.%11

velocity (ft/s) ₌ %

₌!"!2#2

P (m)₌

!"#!2*

(m)₌

!"!'!2

S = (V * n * R -2/3)2

Percent of (or ratio to) full depth ($!! ifflowing full) = (!$!!)

A (m2)


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+n case of half flow

Calculation

IN!"S #!"!"

n ₌ %.%11 D (in) ₌ +DIV/%,

₌ %.%%%%

V (&t/') ₌ +DIV/%,

slope () ₌ %

₌!"!2#2

P (m)₌

!"#!2*

(m)₌

!"!'!2

D = (6.42 *Qn /S 1/2)3/8

,(m/s)

A (m2)


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0aulic Raiu' o& a0tiall ill Ci0cula0 Conuit' (i')

Inut' to calculat 'lo

Percent filling of pipe = .!

Pipe +nside Diameter d = 2!"2 mm

Calculation'

Pipe adius r = !"$!$' m

0low Depth h = !"!'!&'

1entral Angle = 2"$&

1ircular 3egment Area 4 = !"!!*2

Arc 5ength s = !"2%' m

0low Area A = !"!2#2

!"#!2* m

!"!'!$&% m

Inut' to calculat QVPercent filling of pipe = %!

Pipe +nside Diameter d = $!$"' mm

Calculation'

Pipe adius r = !"!%!* m

0low Depth h = !"!%!*

1entral Angle = "$#2

1ircular 3egment Area 4 = !"!!#$

Arc 5ength s = !"$%&' m

0low Area A = !"!!#$

!"$%&' m!"!2%# m

m2

m2

6etted Perimeter P6

=

7ydraulic adius 7 =

m2

m2

6etted Perimeter P6

=

7ydraulic adius 7 =


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0aulic Raiu' o& a0tiall ill Ci0cula0 Conuit' (i')

lo5 Dt7 0

1ircular 3egment Area 1ircular 3egment Area

Arc 5ength Arc 5ength

0low Area 0low Area

6etted Perimeter 6etted Perimeter

7ydraulic adius 7ydraulic adius

lo5 Dt7 90

θ

4

r

s

r

h

s

4

θ

θ

h

r

4

θ=2arccos

(r−h

r )

k =r2 (θ−Sinθ )

2

s=r×θ

A=k

PW =s

R H =

A

Pw

θ=2arccos

(r−h

r )

k =r2 (θ−Sinθ )

2

s=r×θ

A =πr 2−k

PW =2πr −s

R H =

A

Pw


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Su0&ac :at0ial

:annin;


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3teel - ew unlined !"!$$

3teel - iveted !"!$&

?itrified 3ewer !"!$ - !"!$%

6ood - planed !"!$2

6ood - unplaned !"!$

6ood stove pipe small diameter !"!$$ - !"!$2

6ood stove pipe large diameter !"!$2 - !"!$


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Copy of flow, slope &pipe dia. calculation using manning's formula (2).xls

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