## VOL. 3, NO. 2, APRIL 2008

ISSN 1819-6608

# ARPN Journal of Engineering and Applied Sciences

©2006-2008 Asian Research Publishing Network (ARPN). All rights reserved.

www.arpnj

# ournals.com

slope lead to the decrease of compression of the stream lines.

was changed and other parameters such as upstream slope and step height were constant as following:

Therefore in order to maximize the discharge coefficient of long-throated flume i.e. increasing passing discharge through flume to the extent possible, it is advised to reduce the upstream slope of the flume.

3.3. The Effect of downstream slope of long-throated flume on the discharge coefficient (Cd)

The upstream slope was 3:1 and step height (p) was 7.62 cm (flumes C and F and flumes E and G).

The upstream slope was 2:1 and step height (p) is 15.24 cm (Flumes I, L and N and also J and M). Figures 7 and 8 show the discharge coefficient as a function of H1/L for flumes of C and F and also flumes of E and G respectively.

In order to investigate of downstream slope of long-throated flume on the discharge coefficient (Cd), a comparison was made between calculated discharge coefficient of flumes when the upstream slope of the flume

Figures 9 and 10 show the discharge coefficient as a function of H1/L for flumes of I, L and N, and also for flumes of J and M respectively.

P=7.62 cm, Upstream Slope= 3:1

1.02

1

0.98

0.96

Cd

0.94

0.92

0.9

Flume C (D.S. is Vertical )

0.88

Flume F (D.S. is 6:1 )

0.86

0

0.2

0.4

0.6

0.8

1

H1/L

Figure-7. Coefficient discharge of flumes C and D as a function of downstream slope and H1/L when step height (p) is 7.62 cm and upstream slope is 3:1.

P=7.62 cm, Upstream Slope= 2:1

1

0.98

0.96

0.94

Cd

0.92

0.9

Flume G (D.S. is 10:1 )

0.88

Flume E (D.S. is 6:1 )

0.86

0

0.2

0.4 H1/L

0.6

0.8

1

Figure- 8. Coefficient discharge of flumes G and E as a function of downstream slope and H1/L when step height (p) is 7.62cm and upstream slope is 2:1.

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