| 论文简介 |
Submerged steam jet condensation is widely applied in the industry, and the condensation oscillation
during the condensation process is highly related to the safe operation of devices. The first dominant frequency has been frequently studied; thus this study focuses on the characteristic of the second dominant
frequency of supersonic steam condensation oscillation. Results show that the second dominant frequency is generated by the oscillation of the detached steam bubble. The frequency value of the supersonic steam is lower than that of the sonic steam, and increases with the design pressure ratio. Two
different methods, namely, experimental correlation and theoretical calculation, are proposed to obtain
the second dominant frequency. Moreover, its propagation characteristic is investigated under different
operation conditions. An energy peak, which corresponds to the position where the steam bubble separates, always appears. The energy amplitude peaks at a low design pressure ratio when the steam mass
flux is not larger than 600 kgm2s1, and it peaks at a high design pressure ratio when the steam mass
flux increases. A theoretical method is established to obtain the second dominant frequency energy distribution, and its effectiveness is verified against experimental results. Furthermore, owing to the barrier
effect of steam plume, the upstream deviation is slightly higher than the downstream deviation. |
(创新港)
