Definition of the Single Drop Breakup Event
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- 作者：Jannike Solsvik ; Sebastian Maaß ; Hugo A. Jakobsen
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2016
- 出版时间：March 16, 2016
- 年：2016
- 卷：55
- 期：10
- 页码：2872-2882
- 全文大小：656K
- ISSN：1520-5045
文摘
Experiments are performed to record data of single drop breakup events in turbulent flow (stirred tank conditions) for improved understanding of the breakup phenomena. Different interpretations can be made of a multiple breakup event, in particular, either the initial breakup can be evaluated, or the entire breakup cascade can be considered. The examining of these two breakup definitions in the present study reveals that the binary breakup event, which is the most frequent used assumption for the number of daughter drops in the literature, is only a rough assessment of the physical truth. For a 1 mm toluene drop up to 47 daughter drops as a consequence of an entire breakup sequence were counted and the arithmetic average value was 11.7 with standard deviation of 7.7. The corresponding average value for the initial breakup was 2.39. By high-speed imaging it is possible to break down the breakup cascade into binary breakups. However, the isolation of these individual breakups is a strong simplification of the breakup process. The breakups in the cascade are triggered by the initial breakup and are not statistically independent. It is more meaningful to evaluate not only the initiation of a drop breakup but the whole sequence of the breakup cascade. The breakup time of the two breakup definitions appears significantly different. For a 1 mm toluene drop the difference in the arithmetic breakup time was 129 ms. The relative number distribution of the breakup time is wider for the breakup cascade than for the initial breakup as it is influence by the wider range and higher number of daughter drops. Resolution limitations of the camera used did not allow determination of the complete daughter size distribution of the final drop population of the breakup cascade with sufficient accuracy. Two different experimental set-ups were used to verify the general trends of the breakup definitions.