<p> This investigation is an original study in nucleate
pool boiling heat transfer, consisting of two parts: an
experimental study and a theoretical study. The experimental
study was performed with water boiling at atmospheric pressure
on a single copper surface. Two different levels of heat
flux were investigated. For the lower level of heat flux
(92.21 kW/m2), three different levels of subcooling (0, 6.5,
12°C) were studied and for the higher level of heat flux
(192.11 kW/m2), two different levels of subcooling (0, 7.5°C)
were studied as well. </p> <p> The cross-spectral density function ·and the crosscorrelation
function were used to determine the time elapsed
(-r) between the start of bubble growth at two neighbouring
active sites with separation (S). The experimental results
indicate that for the lower level of heat flux at three
different levels of subcooling, the separation (S) and the
time elapsed (-r) are related. For the higher level of heat
flux at 0°C subcooling it was not possible to detect any
correlation, but for the 7.5°C subcooled condition a weak
correlation was found to exist. For the lower level of heat
flux, all the experimental data for the saturated and subcooled
boiling conditions plotted as (S-Rd) versus (T-Tg) drew
together into a single curve, indicating that a single
relationship could fit all the data. </p> <p> Three different theoretical models were devised in an attempt to·explain the experimental observations. The
first model involved heat diffusion in the water; the second
model was based upon the disturbance caused by the propagation
of a pressure pulse in a mixture of water and
vapour and finally the third model involved heat diffusion
in the solid. The first two models failed to give satisfactory
agreement with the experimental results, but the theoretical
predictions corresponding to heat diffusion through the
solid gave good agreement with the experimental findings. </p> / Thesis / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/20315 |
| Date | 11 1900 |
| Creators | Sultan, Mohammed |
| Contributors | Judd, Ross, Mechanical Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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