Measurement of mass flow in large pipes using small turbine-type flowmeters is discussed. Experiments for determining accuracy of flowmeter and applicability to various types of flow measurement are reported. Illustration of turbine flowmeter and calibration curve are included

Hobart, H. F.

Minkin, H. L.

English

NASA Technical Reports Server

rn/sec 
Figure 2. -Velocity (misec) measured by cali-
bration facility. 
Figure 1. - 2. 54-cm Turbine Meter in 7.62-cm Pipe.
3. 
2. 
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November 1972
	
B72-10631 
NASA TECH BRIEF	
11 11 
Lewis Research Center	
_4V 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
USE OF SMALL TURBINE-TYPE FLOWMETERS
TO MEASURE FLOW IN LARGE PIPES
Small turbine-type flowmeters have been used in large 
pipes as velocity detection devices to determine total mass 
flow in the pipes. The method allows the use of small, 
inexpensive, and easily calibrated flowmeters to determine 
mass flow in large pipes in lieu of larger, more expensive 
flowmeters. 
Feasibility experiments were conducted with liquid 
hydrogen, but the results are applicable to all liquids. A 
calibrated one-inch diameter turbine-type flowmeter was 
placed in a three-inch diameter pipe. The flowmeter was 
placed in the position shown in Figure 1 primarily for 
convenience. Consideration, however, was given to the 
velocity profile in the pipe, and the meter was positioned 
to measure an average velocity. Velocities measured by 
the flowmeter were consistently slightly higher than the 
actual average velocities in the pipe, however, as shown in 
Figure 2. This higher result is attributed to (1) distortion 
of the velocity profile by the meter, and (2) systematic 
shift of the average-velocity radius with bulk velocity. The 
first effect would diminish as pipe size increased. The 
second effect can be accounted for by assigning a flow 
coefficient for the installation. A calibration of each 
installation is therefore necessary.
The experiments conducted show the method to be 
feasible and, with further attention to design detail and 
the possible use of multiple detectors, the method should 
be practical and inexpensive for measuring flow rates in 
large pipes where the size and cost of metering devices 
becomes prohibitive. 
NOTE: 
No further documentation is available. Specific ques-
tions, however, may be directed to: 
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B72-10631 
PATENT STATUS: 
NASA has decided not to apply for a patent. 
Source: H.L. Minkin and H.F. Hobart

Lewis Research Center
(LEW-1 1851) 
Category 06 
This documentwas prepared under the sponsorship of the National	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States 	 will be free from privately owned rights.
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Use of small turbine-type flowmeters to measure flow in large pipes

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