Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317195
Title: Experimental and theoretical studies of turbine meters in two-phase flows.
Author: Mark, Philip Antony.
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 1992
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Abstract:
This thesis presents the findings from a three year research project into the performance of turbine meters in two-phase flows. The aim was to determine the geometrical changes needed to be made to the rotor design to allow it to register total volumetric flow when subjected to two-phase flows. A single-phase model is presented based on airfoil theory and including retarding torque terms, velocity profile and blade interference effects. Differences of less than 1% between experimental and theoretical results, over the operating range of the meter are shown. The performance of a range of meters in various two-phase flows is discussed. With the exception of the 40 degree rotor in water/air the results may be summarized as follows. At low flow rates, of between 5 and 20 to 30l/s, the meters tend to underestimate total volumetric flow by up to -10% at void fractions of 25%. The greater the void fraction the greater the underestimation. At high liquid flow rates, above 30 to 40l/s, the meters overestimate total volumetric flow rate by as much as 8% at a 25% void fraction. A reasoned arguement is presented to explain the performanceof the meters in two-phase flow. This is based on phase distribution effects, influenced by the varying flow patterns, which alters the magnitude of the driving torque developed radially along each blade. Using this explanation the single-phase model is developed to encompass two-phase flow. Agreement between experimental and theoretical results is good, particularly in that the sense of the meter error is correctly predicted by the model. Quantatively, errors of less than 2% are achieved. From this model, it was apparent that simple geometrica1 changes to the rotors' design were unlikely to bring about the changes in performance needed to meet the original aim of the project. It must therefore be accepted that, in its existing form and using established pulse total ising techniques, the turbine meter is not suitable for use as a two-phase flow measurement device. The author has discovered a relationship between fluctuations in rotor angular velocity and flow void fraction. It is shown that after suitable processing a single characteristic may be used to describe the meters' response to all void fractions up to 25%, the limit of the test facilities. After calibration of the meter, at a single void fraction, it can be used to indicate both void fraction and flow rate directly. Even at this early stage of development, errors of less than 10% are being achieved in indicated void fraction. This technique is covered by a patent, the rights to which are held by the DTI as the funding body.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.317195  DOI: Not available
Keywords: Fluid mechanics Fluid mechanics Testing Laboratories
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