Browsing by Author "Lawther, KR"
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- ItemRadial heat transfer at the wall in packed beds(Australian Atomic Energy Commission, 1967-05) Chan, BKC; Lawther, KRA literature survey indicates that adequate mathematical models are available for the study of heat transfer in packed beds. However, experimental data have been obtained at low Reynolds numbers only, below 3500. Experimental results are reported for a 7 in. diameter bed packed with 0.489 in. and 0.658 in. diameter glass spheres, with preheated air as the fluid flowing in the bed. Results indicate that the bed-to-wall heat transfer coefficient hw, based on the wall temperature and a bulk gas temperature, may be best correlated by the relation Nu = 2.35 Re 0.63 to a standard deviation of 11.4 per cent for values between 2,000 and 15,000.
- ItemStudies of small particle suspensions for L.M.F.R. Part VI concentration profiles across a bend and vertical pipe(Australian Atomic Energy Commission, 1958-09) Cairns, RC; Lawther, KRThis report completes the work on suspension studies for L.M.F.R. Concentration profiles have been measured for a tungsten suspension flowing through a smooth elbow and a vertical pipe. It has been shown that uniform suspension at a smooth elbow is not achieved for velocities up to 13.8 feet per second. Approximately four feet of vertical pipe is required after the smooth elbow to destroy the gradients set up in a horizontal pipe for velocities of approximately 3 and 13.5 per second. No evidence for "coring" was found.
- ItemStudies of small particle suspensions for L.M.F.R. Part IV concentration gradients in flowing suspensions(Australian Atomic Energy Commission, 1958-07) Cairns, RC; Lawther, KRA radiometric method and the apparatus used to measure concentration gradients in flowing suspension are described. Both iridium 192 and thulium 170 sources have been used to measure gradients. Traverses of both a horizontal and a vertical pipe, in which a tungsten-water suspension was flowing, have been made. Plots are given for various velocities of the concentration distribution in percent tungsten by weight across the pipe at right angles to the direction of flow. Very turbulent conditions, with velocities in excess of 13.4 feet per second (Re > 161,000) in a 1-in, square pipe, are needed before uniform suspension would be achieved. At 13.4 feet per second, the difference in concentration from top to bottom concentration. Much larger concentration gradients exist at lower velocities. In vertical flow no measurable concentration gradients exist for mean velocities of 2.6 to 6.3 feet per second, (Reynolds number 29,000 to 74,000) in a 1-in square pipe. Striations noticed in previous work near the settling point were again observed in this work.