RESEARCH· ·1970·

B258
HYDROLOGIC TECHNIQUES
1.0
~
Qj
c.
• e
0..
18, 2-3, 0.22
12, 1-3, 0.45
12, 1, 0.74
[] :2.0 feet per second
18, 1-3. 0.23
I:' 0.1 ~
Run No.
u
12 0.17
16 0.13
17 0.11
18 0.17
18, 1, 0.37
16. 2-3, 0.22
16, 1-3. 0.20
17. 2-3, 0.36
17. 1-3, 0.36
[] = 3.2 feet per second
16. 1, 0.33
17. 1, 0.43
0.01 ~1 ----'-------'------'---..___1_._0 ____ ..~--___ ~-----....J
f, IN HERTZ
FIGURE 4.-Efficiency of spatial resolution, 71 (f), as a function
of frequency, f, for three Ott minor propellers tested in an
open-channel flow with an artificially roughened boundary.
iJ = 4.1 feet per second
0.1~--~L---~---L~~----~----~---L~~~
1.0
V = 5.0 feet per second
W, IN RADIANS PER SECOND
n1easuren1ents was taken in the Atrisco Feeder Canal,
15 miles north of Albuquerque; the second set in the
Bernardo conveyance channel, 70 1niles· south. The
mean values of the flow parmneters lor the cross section
are given in table 1. All the flowmeter Ineasurements
were taken using an Ott minor 1-3 propeller.
The 1neasurements in a particular vertical were taken
by first traversing the entire depth with the hot-fihn
sensor, then with the propeller flown1eter; the vertical
positions of the two instrmnents during 1neasurements
were not always the same.
Richardson and McQuivey (1968) report that 111
·,,
EXPLANATION
Radius of
oscillation,
in inches
• 6 0.969
c 0.688
• 0.469
• 0 0.109
FrauRE 3.-Absolute value of the system function, jH(w) j,
as a function of angular frequency, w, for a 1-3 propeller.
Two symbols for the same radius indicate measurements
were .made on different days.
FI.ELD MEASUREMENTS OF TUR'BULENCE-VELOCITY
INTENSITIES AND POWER SPECTRAL DENSITIES
The clatn. were taken at byo cross sections on the Rio
Grande ncar Albuquerque, N. ~1cx. The first set of
TABLE 1.-Flow parameters for the field measurements
Flow parameter
Depth (ft) ________ _
Width (ft) ___ -·- ___ _
Mean velocity
(ft per sec) ______ _
Discharge
(ft a per sec) ____ _
Slope __ - __ - ------­
Shear velocity
.(ft per sec) ______ _
Manning's n ______ _
Bed form _________ _
Atrisco Feeder Canal 1
1. 70
56
2. 13
203
. 00057
. 177
. 024
Ripples and small
dunes.
Bernardo conveyance
cbannel2
2. 80
68
2.46
468
. 00055
. 222
. 028
Dunes and plane
with sediment
motion.
1 Power spectral densities and turbulence intensities were measured. The measurements
of power spectral densities were taken at a velocity or 1.59 feet per second,
mean depth of 1.83 feet, and 12 feet left of canal centerline.
2 Turbulence intensities were measured. Right-hand half of channel had 8- to
12-inch-high dunes, the rest was plane.