Title:Instantaneous Liquid Flow Rate Measurement Utilizing the Dynamics of Laminar Pipe FlowAuthor(s):Bernhard ManhartsgruberAbstract: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.Journal:Journal of Fluids EngineeringPublisher:The American Society of Mechanical EngineersISSN:0098-2202Page Reference:page 121402, 8 page(s)Publishing:12/2008Volume:130Number:12