## Solution for Fundamentals of Fluid Mechanics 7th Edition Chapter 10, Problem 2

by Bruce R. Munson, Alric P. Rothmayer, Theodore H. Okiishi, Wade W. Huebsch
1318 Solutions 12 Chapters 66701 Studied ISBN: 9781118116135 5 (1)

# Chapter 10, Problem 2 : 10.1LP Calibration of Triangular weir. Objective:...

10.1LP Calibration of Triangular weir.

Objective: The flowrate over a weir head. The purpose of this experiment is to use a device as shown in fig. P10.1LP to calibrate a triangular weir and determine the relationship between flowrate Q, and weir head H.

Equipment: Water channel (flume) with a pump and a flow control valve: triangular weir; float, point gage; stop watch.

Experimental procedure: Measure the width b, of the channel, the distance, Px, between the channel bottom  and the bottom of the V-notch . Fasten the weir plate to the channel bottom, turn on the pump, and adjust the control valve to produce the desired flowrate, Q. over the weir. Use the point gage to measure the weir head, H. Insert the float into the water well upstream from the weir and measure the time, t , it takes for the float to travel a known distance ,I. Repeat the measurements for various flow rates (i.e., various weir heads)

Calculations: For each set of data , determine the experimental flowrate as Q=VA, where V=L/t is the velocity of the float (assumed to be equal to the average velocity of the water upstream of the weir) and A=b(Pw+H) is the flow area upstream of the weir.

Graph: On log-log graph paper, plot flowrate Q, as ordinates and weir head, H as abscissas. Draw the best-fit line with a slope of 5/2 through the data.

Results. Use the flowrate weir head data to determine the triangular weir coefficients, for this weir (see Eq. 10.32). For this experiment, assume that the weir coefficient is a constant, independent of weir head.

Data: To proceed, print this page for reference when you work the problem and click here to bring up an Excel page with the data for this problem.

10.1LP