Phipps, Paul Dermot (1981) An investigation into streamline mixing in constrained laminar and turbulent axisymmetrical flow using a mass spectrometer-tracer gas analysis. (MPhil thesis), Kingston Polytechnic, .

Abstract

This study investigates streamline mixing in constrained laminar and turbulent flows using a mass spectrometer-tracer gas technique. The first section of the study is a review of qualitative and quantitative tracer techniques previously employed for gas flow investigations. This is followed by a discussion of the aims of the research programme which were firstly, the development of a mass spectrometer tracer gas technique tor detailed flow phenomenon investigations and secondly, an investigation into the molecular diffusion and mass eddy diffusivity of a streamline of tracer gas when injected into constrained laminar and turbulent flows. A summary of the uses of mass spectrometers prior to this study is also included for completeness. The third section deals firstly with the methods of theoretically predicting molecular diffusion coefficients for gas mixtures, using the 'Kinetic Theory of Gases' and secondly, with the development of the basic three dimensional continuity equations in laminar flow which relate the changes of injected tracer concentration with functions of flow velocity and molecular diffusion coefficient. The inclusion of mass eddy diffusivity terms allowed the development of similar equations related to turbulent flow conditions. A method of solving the resulting second order differential equations is discussed. The construction and necessary calibration of the research rig and its associated instrumentation is dealt with in detail in sections four and five. This includes the calibration and the experimental procedure adopted for use with the quadrupole mass spectrometer. Finally the experimental results are presented and they confirmed that, streamline mixing in constrained laminar flow occurs through molecular diffusion and that it was possible with the mass spectrometer tracer gas technique to measure mass eddy diffusivity in constrained turbulent flow. The turbulent flow results obtained enabled a function for mass eddy diffusivity in constrained turbulent flow to be postulated, however further work would be required in this area to confirm this postulation.

Actions (Repository Editors)

Item Control Page