Artificial roughness standard for open channels: abstract

(1)

7

ABSTRACT

ARTIFICIAL ROUGHNESS STANDARD FOR OPEN CHANNELS

By

August R. Robinson Colorado A & M College Fort Collins, Colorado

Presented before the Engineering Section, Colorado-Wyoming Academy of Science, Boulder, Colorado, May 2, 1952.

(2)

• _ABSTRACT

ARTIFICIAL ROUGHNESS

STANDARD FOR

OPEN

CHAJffiEIS

(Presented before

tho

Engineering Section, Colorado-Wyoming Academy

of

Science, Bou lder, Colorado, May 2�

1952).

There are

tvw

principle equat ions which are used in computing .

d1

soharges

in

open channels. These ares •

(1)

Q

c:

CA RS

(

C

h

a z

y)

(

2

)

Q

c

1.486

AR2

/3

81/2

(

Manning

)

_·

n

The resistance coefficients C and n are assumed to

be

constant for a particular location. Previous investigations h�ve

sh�7ll

that these coefficients may vary as nuch as

100

percent for

the sama seotion. A similar situation existed for pipos until a

new method vms devisod for finding the resistance coefficient

by

using

an

artificial roughness standard and considering the magnitude

of the

Reynolds number.

An artificial

standard

for the roughness �1ich exists in an

open channel is proposed. A design for the ro u@lnass is presented and this roughness

tested

in a range of conditions where the

resistance to flow is due solely t o the roughness.

Av1v:o+ f', kobiYI!iOM.

AnghstaRt

n��bton Engineer Colorado A

& M

College

Fort Collins, Colorado ...