Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664268
Title: A depth-averaged model for non-isothermal rimming flow driven at the surface by droplet impact
Author: Kay, E. D.
ISNI:       0000 0004 5362 4407
Awarding Body: University of Nottingham
Current Institution: University of Nottingham
Date of Award: 2014
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Abstract:
Driven by an application to the combined cooling and lubrication by oil of an aero-engine bearing chamber the research in this thesis studies non-isothermal thin liquid film flow on the inside of a circular cylinder driven at its surface by an air-shear and interfacial flux of liquid droplets. Flow conditions inside the bearing chamber preclude using classical lubrication theory models since these neglect some of the physical effects, specifically inertia and heat convection, which are important to this problem. To this end a depth-averaged approach, based on hydraulics modelling within a lubrication theory framework, is adopted which ensures all the relevant physical mechanisms are retained in the model for the film. In limiting cases the model is shown to be consistent with published models for thin film rimming flow. Leading-order inertial effects were found to extend the range of possible thin-film solutions beyond those predicted by lubrication theory alone. This can allow a smooth progression in solution from low-inertia cases, where the film may feature recirculations and steep-fronts, to high-inertia cases of uniform film flow as the film Reynolds number is increased. The accuracy of the depth-averaged model for film temperature is examined for the case of uniform film flow over a heated flat plate. Here an analytical solution exists and the model is found to give very good agreement with this. Film dynamics and thermal characteristics of the film, in particular those relating to the interfacial mass flux of droplets, are analysed in detail. The depth-averaged model is used to provide insight into the motivating bearing chamber application through calculation of oil film temperature characteristics and a parameter space showing the dependence of film residence times on chamber operating conditions.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.664268  DOI: Not available
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