"Instantaneous Liquid Flow Rate Measurement Utilizing the Dynamics of Laminar Pipe Flow"
, in The American Society of Mechanical Engineers, in Journal of Fluids Engineering, Vol. 130, Nummer 12, Seite(n) 121402, 12-2008, ISSN: 0098-2202
Instantaneous Liquid Flow Rate Measurement Utilizing the Dynamics of Laminar Pipe Flow
Sprache des Titels:
This paper deals with the utilization of the dynamic characteristics
of laminar flow in circular pipes for the indirect measurement of
flow rates. A discrete time state space realization of the transmission
line dynamics is computed via inverse Laplace transform and an identification
and model reduction method based on the singular value decomposition.
This dynamic system is used for the computation of the flow rate at
one end of a pipe section. Special attention is paid to the identification
of the speed of sound and the dimensionless dissipation number of
the pipe section, since exact knowledge of these parameters is crucial
for the reliability of the measurement results. First experimental
validation results are given in a limited range of operating frequencies
between 100 and 2000 Hz. Flow-rate variations within +/-1.2 l/min
have been measured with an uncertainty of +/- 0.07 l/min at the
95 % confidence level. The test fluid was mineral oil.