Solidification and Melting Processes of a binary Mixture

二元混合物的凝固和熔化过程

• 批准号: 02650162
• 负责人: SASAGUCHI Kengo
• 金额: $ 1.22万
• 依托单位: Kumamoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650162/
• 关键词: Solid; Liquid Phase Change; Binary Mixture; Solidification and Melting; Experiment; Numerical Analysis

Experiments for solidification have been conducted using aqueous ammonium chloride (NH_4Cl-H_2O) as a binary mixture. Effects of the initial concentration and the initial superheat of the solution, the orientation and the temperature of a cold surface, and attached brass plates to the cold surface on the solidification process have been systematically examined from observations of timewise variation of the solidification morphology and from measurement of temperature distributions. Numerical calculations have also been performed for various conditions. Obtained conclusions are summarized as follows :(1) Since solute-rich fluid is released from the solid/liquid two-phase region when the initial concentration, C_o, is set at a value which is smaller than the eutectic one, C_e, solutal convection largely affect the two phase region when the cold surface is located at the side and at the bottom of the cell, and various solidification morphologies are observed.(2) When the initial concentration is smaller than the eutectic one, the effect of the initial superheat is larger for a larger initial concentration. A large initial superheat causes dense dendrites and the retardation of the development of the two-phase region.(3) When C_o is larger than C_e and the cold surface is located at the bottom, several projections and channels are observed on the liquid/two-phase interface and in the two-phase region, respectively.(4) From the melting experiments, it is shown that for small initial concentrations the phenomenon is similar that for C_o=O (the pure water), but for C_o=C_e the thermal convection is coupled with the solutal one, a complicated interface is observed, and the melting rate becomes larger.(5) Results obtained by the developed numerical method show good agreements with experimental ones, and detailed information (e. g. concentration distribution), which is difficult to measure, is obtained.

已经使用氯化铵（NH_4CL-H_2O）作为二元混合物进行了凝固实验。从凝固过程的凝固过程中的初始浓度和溶液的初始过热，冷表面的方向和温度以及附着的黄铜板的影响，并从固化过程的观察结果中进行了系统的检查。还针对各种条件进行了数值计算。总结如下：（1），由于富含溶质的液体是从固体/液体两相区域释放出来的，而当初始浓度（C_O）设置为一个小于Eutectic的值（C_E C_E，Solutal对流）小时，而当冷表面较小时，当冷表面的侧面和固体底部较小时，在很大程度上会影响两个相位的固体区域，而不是固体的底部（2）。共晶型，初始超热的效果对于较大的初始浓度更大。大型初始过热会导致密集的树突和两相区域的发展的延迟。（3）当C_O大于C_E并且冷表面位于底部时，在液体/两相界面上观察到几个投影和频道，分别在两相区域以及在两阶段区域中。 （纯水），但是对于C_O = C_E，热对流与溶质的对流相结合，观察到复杂的界面，并且熔融速率更大。（5）通过开发的数值方法获得的结果显示了与实验性的良好协议，并获得了详细信息（例如，浓度分布），很难获得测量。

项目成果

K.Sasaguchi: "AN EXPERIMENTAL STUDY ON SOLIDIFICATION OF A BINARY MIXTURE (EFFECTS OF VARIOUS PARAMETERS ON THE MORPHOLOGY)" Proceedings of the Third ASME/JSME Thermal Engineering Joint Conference,to be published.(1991)

K.Sasaguchi：“AN EXPERIMENTAL STUDY ON SOLIDIFICATION OF A BINARY MIXTURE (EFFECTS OF VARIOUS PARAMETERS ON THE MORPHOLOGY)”第三届 ASME/JSME 热工联合会议论文集，待出版。(1991)

笹口 健吾: "2成分相変化材の凝固過程(種々のパラメ-タが凝固形態に及ぼす影響)" 日本機械学会論文集. 57. 2315-2322 (1991)

Kengo Sasaguchi：“双组分相变材料的凝固过程（各种参数对凝固形式的影响）”日本机械工程师学会会刊 57. 2315-2322（1991）。

笹口 健吾: "熱伝導性の水平板を有する矩形容器内の非定常層流自然対流(グラスホフ数の影響)" 日本機械学会論文集. 57. 1057-1064 (1991)

Kengo Sasaguchi：“带有导热水平板的矩形容器中的不稳定层流自然对流（格拉肖夫数的影响）”日本机械工程师学会会刊 57. 1057-1064 (1991)。

笹口 健吾: "多孔質層内の固ー液相変化(フィン付き伝熱面回りの非定常熱伝達:数値解析)" 日本機械学会論文集.

Kengo Sasaguchi：“多孔层中的固-液相变（翅片传热表面周围的不稳定传热：数值分析）”日本机械工程师学会会议录。