PIPE FLOW MODELING FOR ULTRASONIC FLOW MEASUREMENT
H. Jeanneau, M. Piguet
Abstract:
In many industrial applications, the precise measurement of volumetric flow- rates is of crucial importance for economic or safety reasons. Flowmeters are generally installed in perturbed flow conditions. The measured value is then affected by a systematic error which can reach several %. EDF has developed a numerical tool to estimate the error introduced by the flow disturbances on the flow-rate measurement with ultrasonic flowmeters or differential pressure devices. The tool is based on a 3D CFD program which determines the flow profile. A module allows the simulation of ultrasonic flowmeters and differential pressure devices. This paper deals with ultrasonic flowmeters which are very sensitive to the flow profile through the parameter K (profile factor). Two configurations are presented in this paper: - a double bend out of plane, - a pipe representative of the primary loop in nuclear power plant. In each case, both modelisation and experimental tests have been carried out to determine the profile factor K representative of the flow conditions, which should be used for the measurement with the ultrasonic flowmeter to reduce the error introduced by the disturbances. The influence of different parameters has been studied. Experimental and calculated profile factors are compared. In both configurations, the simulation results are in good agreements with the experimental data. The tendency is well predicted by the tool and the typical difference between experimental and numerical K is around 2% or 3%. The profile factors are also compared to the classical K (Prandtl Model) used and proposed by manufacturers, which is calculated from an analytic model of fully developed profile. The gain realized by using simulation is significant.
Keywords:
ultrasonic flowmeter, CFD, experimental, profile factor, uncertainties, gain
