USSR Cooperative Research on Heat and Mass Transfer During Directional Solidification in a Centrifuge

苏联合作研究离心机定向凝固传热传质

• 批准号: 9019536
• 负责人: William Wilcox
• 金额: $ 1.99万
• 依托单位: Clarkson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9019536&HistoricalAwards=false
• 关键词: USSR; Cooperative; Research; Heat; Mass

This is a joint research project between Clarkson University and the Laboratory of Materials Science in Space at the Space Research Institute (IKI) of the USSR Academy of Sciences to elucidate the transport phenomena that occur during directional solidification in a large centrifuge. Clarkson University and the Space Research Institute (IKI) are uniquely configured to accomplish this goal. Prior research on transport phenomena in large centrifuges has shown unexpected results that have not yet been fully explained. For example, a critical rotation rate was found for the onset of temperature oscillations, with a higher critical rotation rate for cessation of temperature fluctuations. Several directional solidification experiments exhibited a "magic g" at which impurity segregation and microstructure became what one would expect from a complete lack of convection in the melt during solidification. Theoretical models will be developed at Clarkson University to predict convection and mass transfer in the melt, temperature distribution in the solid, solid-liquid interface shape, and freezing rate during solidification in the centrifuge. Predictions of these models will be compared with experiments carried out on the Soviet apparatus. Clarkson and IKI scientists will work together to modify the Soviet apparatus to permit temperatures to be measured inside the material during solidification, and to determine the heat transfer coefficient between the material and the steel cartridge. We will add either current interface demarcation or vibration interface demarcation to allow us to determine the interface shape and freezing rate versus time. We will also cooperate in development and execution of flow visualization experiments in the centrifuge.

这是克拉克森大学和 和空间材料科学实验室 研究所（伊基）的苏联科学院， 阐明运输过程中发生的现象， 在大型离心机中定向凝固。 克拉克森 大学和空间研究所（伊基）是独一无二的 配置来实现这个目标。 以前的研究 大型离心机中的输运现象显示出意想不到的 这些结果尚未得到充分解释。 比如说， 一个临界转速被发现的发病 温度振荡，具有较高的临界转速 停止温度波动。 几 定向凝固实验显示出一种“神奇的g” 杂质偏析和显微组织变成什么样 我们可以预期，由于大气中完全没有对流， 在凝固过程中熔化。 克拉克森大学将开发理论模型， 预测熔体中的对流和传质，温度 - 在固体、固-液界面形状中的分布，以及 在离心机中固化期间的冻结速率。 这些模型的预测将与实验进行比较 在苏联机器上进行。 克拉克森和伊基 科学家们将共同努力， 以允许测量材料内部的温度 在凝固过程中，并确定热传递 材料和钢筒之间的系数。 我们 将添加当前接口分界或振动 接口划分，以允许我们确定接口 形状和冷冻速率与时间的关系。 我们也会配合 在流动可视化实验的开发和执行中， 在离心机里。