Theoretical, Numerical, and Experimental Study of the Time of Flight Flowmeter

Abstract

Time-of-flight flowmeters offer advantages over other flowmeter types since these are less sensitive to the physical properties of the fluid. However, calibration of the flowmeter for a particular working fluid is still required. A flowmeter that does not require re-calibration with different fluids is desirable in many applications. This paper investigates the performance of a device that measures the time of flight of a heat pulse in a gas stream to determine the flow rate in a pipe. A fusion of the theoretical, experimental, and numerical data is used to suggest a gas-independent correlation function between the response time and flow rate. In particular, the numerical data augmented by the theoretical analysis to account for the wire response time is validated against experimental data and used to further enhance the experimental data set. Nitrogen, helium, and tetrafluoroethane (R134a) are investigated, as these gases provide a wide range of physical and thermodynamic properties. Simulated results match the trends of experimental data well and allow good qualitative analysis. The results also show that using detected pulse width information together with the time of flight can yield a 20% reduction in the errors due to gas type than by using time of flight data alone. This gives a relatively gas-independent function over a dynamic range of 1:400.

A Visual Software Implementation of Numerical Simulation for Transient Process of Pipeline Network System of Water Supply Project

“…If the flowmeter has no influence on the flow state of water in the pipeline and has no head loss, such as electromagnetic flowmeter and ultrasonic flowmeter, the flowmeter can be equivalently regarded as a part of pipeline and then simulated in the software. If the flowmeter has head loss, such as differential pressure flowmeter and thermal time of flight flow meter [42], the flowmeter cannot be simulated in the software.…”

Investigation of a GDI injector with an innovative flowmeter for high-pressure transient flows

“…In the turbine flowmeters, the frequency generated by the rotation of a rotor is directly proportional to the flowrate. 2 These steadily calibrated devices can be applied to measure unsteady flowrates, 3 but only pulsating 4,5 or intermittent 6 ones with a lower frequency than 1 kHz can be considered.…”

Instantaneous flowrate measurements in high-pressure liquid flows

“…The frequency caused by the impeller rotation, which is directly correlated with the flowrate, is measured in turbine flowmeters [2]. These devices, calibrated in steady state conditions, can be used to monitor unsteady flow rates [3], although only pulsing [4,5], or intermittent [6] flows with frequencies less than 1 kHz can be considered.…”