LETTER TO THE EDITOR: The two-stage increase in negative pressure with repeated cavitation for water in a metal Berthelot tube
LETTER TO THE EDITOR: The two-stage increase in negative pressure with repeated cavitation for water in a metal Berthelot tube
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致编辑的信：金属 Berthelot 管中的水通过重复空化作用两阶段增加负压
DOI：
10.1088/0022-3727/21/10/015
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
T. Ando
中科院分区：
文献类型：
--
作者：
Y. Ohde;M. Ikemizu;H. Okamoto;W. Hosokawa;T. Ando
为了研究空化历史对金属Berthelot管中水系统负压的影响，作者制作了一根带有铜塞的不锈钢管子。对水和铜塞进行了空气吹扫前处理。该系统在适当的温度范围内多次交替加热和冷却。在Berthelot方法中，对于单次加热和冷却程序(一个温度循环)，在空化之前，由于温度下降而产生的负压最高。各个温度周期的负压虽然分散，但呈现出两个阶段增加的趋势，即前期为陡峭阶段，后期为渐变阶段。即使在水交换后的一系列温度循环中，只要使用相同的塞子进行密封，空化历史的类似影响也会持续存在。负压为-76atm(-7.7兆帕)，高于报道的金属管中的水的值，在总共850个温度循环后，通过两次水交换在46摄氏度下形成。这两个阶段的增加被认为是由于系统中较弱的空化核的逐次消退造成的。
The authors made a stainless steel tube with a copper plug to study the effects of cavitation history on negative pressure for a system of water in a metal Berthelot tube. The water and the copper plug were pre-treated for air purging. The system was alternatively heated and cooled over appropriate temperature ranges many times. In the Berthelot method, the negative pressure generated with failing temperature becomes highest just before cavitation for a single heating and cooling procedure (one temperature cycle). Negative pressures for respective temperature cycles, though scattered, exhibited an increasing trend through two stages, a steep stage for earlier cycles and a gradual stage for later cycles. A similar effect of the cavitation history persisted even in a series of temperature cycles after exchanges of water, so long as the same plug was used for sealing. The negative pressure -76 atm (-7.7 MPa), which is higher than the values ever reported for water in a metal tube, developed at 46 degrees C through two water exchanges after a total of 850 temperature cycles. The two-stage increase was considered to be caused by the successive fading of the weaker cavitation nuclei in the system.