The MIIS Eprints Archive: No conditions. Results ordered -Date Deposited. 2021-08-05T15:43:12ZEPrintshttp://miis.maths.ox.ac.uk/images/sitelogo.gifhttp://miis.maths.ox.ac.uk/miis/2011-12-01T13:18:16Z2015-05-29T20:03:38Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/440This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/4402011-12-01T13:18:16ZThermodynamics of airburn of carbon anodes in aluminium reduction cellsHall-Heroult process.N. Stokes2011-12-01T13:10:13Z2015-05-29T20:03:35Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/439This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/4392011-12-01T13:10:13ZResonant whirling of two-piece propshafts in rear-wheel-drive carsMany modern cars with rear-wheel drives have a two-piece, rather than the traditional one-piece, props haft (or tail-shaft). The two-piece shaft requires less floor clearance, and hence a smaller floor tunnel, and does not suffer from the high-speed twisting resonances to which the one-piece shaft is susceptible.

The two-piece shaft is, however, susceptible to a lower speed, high load (high torque) phenomenon in which the propshaft whirls with increasing amplitude until its restraining rubber bush is fully compressed in its mounting bracket, causing a thump sound. The whirling amplitude builds up periodically, so that a regular series of thumps is heard at a frequency of about 5 per second.

The effect is very sensitive to the properties of the rubber bush and to its temperature. Different designs of bush are used by different makers, each with the purpose of minimizing both the whirling problem and the transmission of other vibrations to the car body.

GMH has a particular design which it would prefer not to vary, because of retooling costs. It can however vary the properties of the rubber material itself. By trial and error it has achieved rubber properties which control the whirling problem to an acceptable level under normal conditions. GMH posed the question, to the MISG, of whether one can give theoretical guidelines for optimal rubber properties. This might lead to improved control of the whirling problem. It would also be useful for new and modified propshafts, if it could replace the tedious trial and error process previously employed.

GMH were also anxious to gain a better understanding of the whirling phenomenon, and felt, with us, that a mathematical description of the phenomenon was a prerequisite for the study of the rubber properties. The thumping phenomenon is observed at both 40 and 80 kph approximately, although the phenomenon had a different quality at these two speeds.D. Gates2011-12-01T13:03:04Z2015-05-29T20:03:32Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/438This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/4382011-12-01T13:03:04ZManagement of interstate rail rollingstockThe Study Group was asked to develop a methodology to allow more efficient and effective direction of empty wagon movements. The Study Group chose to develop two linear programming approaches. One was for allocating empty wagons, and the other modelled both empty and full wagons. Although large in size, the models were otherwise feasible, showing that, conceptually, the method would work. However, there is still a major amount of development work required to implement the system.H. Barr2011-12-01T13:00:35Z2015-05-29T20:03:28Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/437This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/4372011-12-01T13:00:35ZFlows in gas pipelinesSafe and efficient use of compressors in a pipeline network is quite complex since high pressures and pressure fluctuations may damage the pipeline. As a consequence, the problem posed to the Study Group was to examine to what extent mathematical modelling can be used to provide guidance for the operation of compressor stations.F. Hoog2011-12-01T12:57:12Z2015-05-29T20:03:24Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/436This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/4362011-12-01T12:57:12ZDroplet cooling of galvanised ironN. Barton2011-12-01T12:56:05Z2015-05-29T20:03:21Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/435This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/4352011-12-01T12:56:05ZCompression of high quality audio signalsM. Cameron