Development of the bouble difusion augmentator of interface instability type by using an unsteady Lorentz force

利用非定常洛伦兹力研制界面不稳定型球泡扩散增强器

基本信息

批准号：
05555057
负责人：
YAMANE Ryuichiro
金额：
$ 5.12万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Analyzes and experiments were conducted for the development of the bouble difusion augmentator of interface instability type by using an unsteady Lorentz force, and following conclusions were derived :(1) In the case that the unsteady Lorentz force is generated by uniform horizontal AC magnetic field :i) Unstable waves generated on the liquid metal surface oscillate in the same frequency as the AC magnetic field.ii) Unstable conditions are dependent on 4 parameters ; the magnetic Reynolds number Rm, the Stuart number Np, the weber number we , and the Reynolds number Re.iii) The waves which wave vector are parallel with the magnetic field are most unstable.iv) In the case that both the Weber number We and the Reynolds number Re are fixed at some values, unstable boundary moves upward in tha omega-Np plane with a decrease of the magnetic Reynolds number, and the system becomes stable ; however, the relation between the frequency of the AC magnetic field and the wave number of the unstabl … More e wave hardly changes.v) In the case that both the magnetic Reynolds number Rm and the Reynolds number are fixed at some values, unstable boundary moves to the right-hand side in the omega-Np plane and the wave number of the unstable wave decreases with a decrease of the Weber number.vi) In the case that both the magnetic Reynolds number Rm and the Weber number are fixed at some values, unstable boundary moves upward in the omega-Np plane ; however, the relation between the frequency of the AC magnetic field and the wave number of the unstable wave hardly changes.vii) The frequency of the AC magnetic field becomes higher, the induced electric current concentrate around the free surface and the temperature rises severely.viii) Relatively strong magnetic field with a high frequency are needed for the genaration of unstable waves in the actual machine.(2) In the case that the unsteady Lorentz force is generated by simulteneous imposition of horizontal DC and AC magnetic fields :i) The waves with the same frequency as the AC magnetic field appear on the liquid metal surface.ii) The optimum strength of the DC magnetic field that gives the waves of the largest amplitude exists and changes in value according to the strength of AC magnetic field.iii) The oscilation mode depends not on the distribution of the magnetic field but on the shape of the container. Less

对非定常洛伦兹力界面不稳定型球泡扩散增强器的研制进行了分析和实验，得到以下结论：(1)当非定常洛伦兹力由均匀水平交流磁场产生时： i) 液态金属表面产生的不稳定波以与交流磁场相同的频率振荡。ii) 不稳定条件取决于 4 个参数；磁雷诺数 Rm、斯图尔特数 Np、韦伯数 we 和雷诺数 Re。 iii) 波矢与磁场平行的波最不稳定。 iv) 在韦伯数 We 和雷诺数 Re 都固定在某个值的情况下，随着磁雷诺数的减小，不稳定边界在 omega-Np 平面上向上移动，系统变得稳定，但交流磁场的频率与不稳定 e 波的波数之间的关系几乎没有变化； .v) 如果两者都磁雷诺数 Rm 和雷诺数固定在某个值，不稳定边界在 omega-Np 平面中向右侧移动，不稳定波的波数随着韦伯数的减小而减小。vi)当磁雷诺数Rm和韦伯数都固定在某个值时，不稳定边界在omega-Np平面上向上移动，而交流磁场的频率与不稳定波的波数之间几乎没有关系； vii) 频率交流磁场的强度变高，感应电流集中在自由表面周围，温度急剧升高。viii)在实际机器中需要相对强的高频磁场来产生不稳定的波。(2)同时施加水平直流和交流磁场产生非定常洛伦兹力的情况：i) 液态金属表面出现与交流磁场频率相同的波。ii) 直流磁场的最佳强度这给出了存在最大振幅的波，并且其值根据交流磁场的强度而变化。iii) 振荡模式不取决于磁场的分布，而是取决于容器的形状。