8/12/2019 HYDRAUL-EXPT#7.b.docx

1/4

8/12/2019 HYDRAUL-EXPT#7.b.docx

2/4

EXPT.No.7-B 2

HYDHYDRAULICS LABORATORY

I. Experiment Objectives

- To observed the characteristics of open-channel flow over a trapezoidal weir.- To determine value of the discharge coefficient for trapezoidal weir.

II. Materials and Apparatuses Required

The apparatuses necessary to perform this experiment are the following:

- Tilting Flume Apparatus- Calibrated Bucket- Stopwatch- Metric Scale- Trapezoidal Weir

III. Procedures

a) Attach the trapezoidal weir to the channel (Flume).b) Measure the width (L) of the trapezoidal weir.c) Turn on the pump and open the control valve until water discharges over the

weir.d) Regulate the flow to maintain a water level in the flow channel so that the weir is

filled to the highest possible level without overflowing the channel.e) Allow a steady flow to develop throughout the entire circuit.f) Measure the height of the water level above the top of the weir as an H to start

the analysis.g) Measure the flow rate with a stopwatch and calibrated bucket.h) For each set of measurements, measure the flow rate at least three times and

take the average.i) Reduce the approach, repeat step e to step h by using different flow rate of

water, which can be done by adjusting the water supply. Measure and record theH and the time to fill a certain volume of water in the bucket.

j) Compute for the theoretical discharge using the equation;

k) Calculate the actual discharge by volumetric method using the formula;

l) Determine the coefficient of discharge of a cipolletti weir:

8/12/2019 HYDRAUL-EXPT#7.b.docx

3/4

EXPT.No.7-B 3

HYDHYDRAULICS LABORATORY

IV. Laboratory Data

TRIAL

ACTUAL DISCHARGE THEORETICAL DISCHARGECOEFFICIENT OF

DISCHARGEVOLUME

(m3)

TIME

(sec)Qa L (m) H (m) Qt Cd Cd (AVERAGE)

1

2

3

COEFFICIENT OF DISCHARGE, Cd

8/12/2019 HYDRAUL-EXPT#7.b.docx

4/4

EXPT.No.7-B 4

HYDHYDRAULICS LABORATORY

V. Observations

__________________________________________________________________________________________________________________________________________________________________________________________________________________

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

VI. Conclusions

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________