Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.586033
Title: The effects of friction reducing polymers on the operation of journal bearings
Author: Hampson, L. G.
Awarding Body: Durham University
Current Institution: Durham University
Date of Award: 1972
Availability of Full Text:
Access from EThOS:
Access from Institution:
Abstract:
As rotating machines become larger, an increasing number of plain journal bearings operate in the turbulent regime. The addition of small amounts of high molecular weight polymers to the lubricant offers an attractive method of counteracting the increased power loss. This effect has previously been investigated for turbulent flow in pipes. Experiments are described on the operation of a four-inch diameter bearing lubricated with a very dilute, aqueous solution of poly(ethylene oxide).It is shown that the film extent in large clearance bearings is very dependent on the operating parameters, A numerical analysis based on the Reynolds equation indicates that a minimum dissipation principle can be used to explain the delay in the formation of a full width film. The transition to turbulence occurred at a Reynolds number of 2000. There was little evidence of Taylor vortices. The bearing friction was significantly affected by the angular momentum of the leakage flow. Very low concentrations of polymer were found to be effective in reducing the friction. Typically, 0.005% by weight causing a reduction of k5% at a Reynolds number of 3500, The bearing was also significantly stabilised against whirling, although the pressure distribution was unchanged. The polymer became ineffective after approximately twenty passes through the bearing. The degradation caused by shearing will probably be the factor limiting commercial exploitation of friction reduction in turbulent bearings.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.586033  DOI: Not available
Share: