Experimental study on the transition of He II boiling modes with the hydrostatic pressure around the Lambda temperature
Experimental study on the transition of He II boiling modes with the hydrostatic pressure around the Lambda temperature
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He II沸腾模式随Lambda温度附近静水压力转变的实验研究
DOI：
10.1007/978-1-4615-4215-5_13
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
T. Toyoshima
中科院分区：
文献类型：
--
作者：
Y. Takashima;M. Murakami;T. Toyoshima
实验研究了He Ⅱ薄膜沸腾模式随静水压力变化的转变。特别注意的是，在λ温度附近的沸腾模式的压力依赖性。为此目的，进行了详细的调查与援助的光学可视化和压力振荡和温度振荡测量。所有的实验都是通过使用一个单一的低温恒温器在整个压力范围内从饱和蒸汽压过冷状态，因为激发的压力振荡是高度影响的几何配置的测试空间在低温恒温器。在过冷沸腾的情况下，在平面加热器上可以看到体蒸汽膜的闪烁，而不是在嘈杂的膜沸腾中观察到的蒸汽泡的重复生长和破碎。发现在中等静压下，在比λ温度稍低的温度下，会激发出规则的压力振荡，这与噪声和过冷膜沸腾模式的不规则振荡有明显的不同。在接近λ温度的温度范围内，随着温度的降低和热流密度的增加，低频尖峰振荡叠加在规则振荡之上。当温度低于λ-温度时，规则振荡消失，沸腾转变为有噪声的膜沸腾。
The transition of film boiling modes in He II with the change of the hydrostatic pressure is studied experimentally. Special attention is paid to the pressure dependence of boiling modes around the λ temperature. For this purpose, detailed investigation is carried out with the aid of optical visualization and the pressure oscillation and the temperature oscillation measurements. All the experiments are conducted by using a single cryostat over the entire pressure range from saturated vapor pressure to subcooled states because the excited pressure oscillation is highly affected by the geometrical configuration of the test space in a cryostat. In the case of subcooled boiling, flickering of bulk vapor film is seen on the planar heater instead of repeated growth and crush of a vapor bubble as observed in the noisy film boiling. It is an interesting finding that a regular pressure oscillation is excited at slightly lower temperature than the λ-temperature for a moderate value of the hydrostatic pressure, which is obviously different from rather irregular ones of noisy and subcooled film boiling modes. With the decrease in the temperature and the increase in the heat flux in the temperature range close to the λ-temperature, low frequency spiky oscillations are superposed on the regular oscillation. At still lower temperatures than λ-temperature, the regular oscillation disappears and boiling turns to noisy film boiling.