Engineering

Publication Search Results

Now showing 1 - 10 of 103

  • (1973) Foster, Brian
    Thesis
    The suspension of solid spheres in fully developed vertical pipe flow has been investigated between particle Reynolds numbers of 2 and 10000 and between pipe Reynolds numbers of 25 and 37000 for sphere to conduit diameter ratios ranging from 0.046 to 0.274. It was found that the drag coefficient obtained in the present study was higher than that reported for spheres suspended or traveling in bounded or unbounded quiescent fluids. The drag coefficient was found to depend upon the particle Reynolds number and the sphere to conduit diameter ratio. The radial position adopted by the spheres was found to be near the conduit axis at particle Reynolds numbers below 80 but near the conduit wall at particle Reynolds numbers greater than 200. A secondary sphere to conduit diameter ratio effect upon radial position was observed when spheres were suspended near the conduit wall. The spheres underwent four distinct modes of motion; the particular mode adopted was primarily dependent upon the particle Reynolds number with a secondary dependency upon the sphere to conduit diameter ratio. Transitions between modes occurred at particle Reynolds numbers which were approximately the same as values reported for changes in the wake structure behind spheres.

  • (1970) Wilkinson, D L
    Thesis



  • (1973) Huyakorn, P. S. (Pongsarl S.)
    Thesis

  • (1975) Clifton, Michael
    Thesis
    The use of reverse osmosis in the treatment of solutions containing a single solute has been the subject of a great deal of research, but very little attention has been given to the question of whether the equations developed to describe the behaviour of single-solute solutions may be applied to solutions containing more than one solute. The present work was aimed at testing the suitability of previously derived transport equations when the solution to be treated contained two solutes, one organic and one inorganic. An important point to be decided was the degree to which interactions between solutes would affect their rate of transfer through the membrane. A commercial reverse-osmosis unit was used in the experimental work. Solution containing a single solute were tested, as well as those containing two solutes; the solutes used were sodium nitrate, sodium sulphate, urea and glucose. Concentrations of ionic substances were measured by conductivity 5 while liquid scintillation counting was used to measure concentrations of organic solutes labelled with radioisotopes. The results of the experiments with single solutes were necessary for the analysis of the results obtained with solutions containing two solutes. The control over experimental conditions and the accuracy of the measurements were superior to those which could be achieved under industrial conditions, and were in no way jeopardized by the use of a commercial unit for such basic research. It was found that the transport equations derived by other workers could be improved upon. In particular, the equations previously suggested to describe the transfer of ionic solutes within the membrane were found to be quite inaccurate. The reason for this inaccuracy seems to be that a certain amount of the electrolyte solute moves through the membrane in an undissociated form. A revised set of transport equations has been suggested. The interaction between solutes was found in most cases to be too small to measure. In cases where interaction was detected it had relatively little effect on the rate of transfer of the solutes.

  • (1977) Nittim, R. (Rein)
    Thesis