Improving multi-phase performance of a Coriolis Flowmeter

Schäfer, Stephan (2025) Improving multi-phase performance of a Coriolis Flowmeter. PhD thesis, University of Glasgow.

Abstract

In this dissertation, a new concept is introduced to improve the multi-phase flow metering performance of an existing Coriolis Mass Flowmeter (CMF) by sensor fusion with an additional differential pressure sensor. Core element of the concept is an empirical functional group of so-called acceleration factors that characterize the correlation of pressure drop over other flow parameters, mainly liquid mass flow rate and amount of entrained gas.

In order to establish these correlations, experimental and numerical data have been produced, analysed and processed. This was done within the laboratory of the predevelopment department of Endress + Hauser Flow in Freising, Germany. The measurements contain a large matrix of flow parameters, vertical as well as horizontal orientations and a step-by-step increment of geometrical complexity. First, the multi-phase pressure drop over single straight tubes was investigated and compared to the current state-of-the-art. Next, an interim stage between the simple geometry of a single straight tube and a CMF was taken by producing and modelling a straight double tube with a true to scale flow splitter that divides the flow into two parallel tubes and merges them back together further downstream, an element highly similar to the inside of a CMF, but without its characteristic bent shape. Lastly, the experimental approach covered the true CMF geometry and was carried out with water-air and glycerine-water-air mixtures as well as complemented by auxiliary investigations regarding the recirculation zone.

The findings of this research make it possible to deploy an iterative algorithm to quantify the liquid mass flow rate of a multi-phase flow for entrained gas contents of up to 30% in volume for Reynolds numbers in the range of 300 to 300,000. Further extension of the validation to a larger parameter range is not ruled out, but was not possible to investigate due to the limits of the laboratory. A meaningful statement about the accuracy of the overall algorithm should only be given after a field test, however the prediction of the acceleration factor functional group appears to be in the range of ±10 % accuracy with most data points with higher Reynolds numbers appearing in the ±5 % accuracy range.

Furthermore, the results of this work can be used for further studies of CMF multi-phase behaviour.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: T Technology > TC Hydraulic engineering. Ocean engineering; T Technology > TJ Mechanical engineering and machinery; T Technology > TP Chemical technology
• Colleges/Schools: College of Science and Engineering > School of Engineering
• Supervisor's Name: Falcone, Professor Gioia
• Date of Award: 2025
• Depositing User: Theses Team
• Unique ID: glathesis:2025-85020
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 09 Apr 2025 14:17
• Last Modified: 09 Apr 2025 14:17
• Thesis DOI: 10.5525/gla.thesis.85020
• URI: https://theses.gla.ac.uk/id/eprint/85020