| 论文简介 |
Submerged steam jet condensation is widely applied in various fields because of its high heat transfer
efficiency. Condensation oscillation is a major character of submerged steam turbulent jet, and it significantly affects the design and safe operation of industrial equipment. This study is designed to reveal the
mechanism of the low-frequency pressure oscillation of steam turbulent jet condensation and determine
its affected region. First, pressure oscillation signals with low frequency are discovered in the downstream flow field through oscillation frequency spectrogram and power analysis. The oscillation frequency is even lower than the first dominant frequency. Moreover, the critical positions, where the
low-frequency pressure oscillation signals appear, move downstream gradually with radial distance
and water temperature. However, these signals are little affected by the steam mass flux. Then, the
regions with low-frequency pressure oscillation occurring are identified experimentally. The affected
width of the low-frequency pressure oscillation is similar to the turbulent jet width. Turbulent jet theory
and the experiment results collectively indicate that the low-frequency pressure oscillation is generated
by turbulent jet vortexes in the jet wake region. Finally, the angular coefficients of the low-frequency
affected width are obtained under different water temperatures. Angular coefficients, ranging from
0.2268 to 0.2887, decrease with water temperature under test conditions. |
(创新港)
