Heat and Mass Transport in Horizontal Two Phase He II Vapor

氦II，或超流氦，是一种存在于2.2K以下的独特流体。除其他性质外，He II具有极高的导热性，并遵循非线性热方程。这一特性鼓励了He II在许多技术设备中的使用，包括超导磁体和间隔基仪器。迄今为止，He II的大部分工作都集中在单相流体的热量和质量传递的研究上，重点是静态和强制流动中的稳态和瞬态传热。在提议的工作中，这将扩展到包括在水平流动中共存的He II/饱和蒸汽。将开发一个水平实验测试设备来测量蒸汽质量、空隙率、质量流量和传热率的影响。实验结果将与基于He II和蒸汽的基本性质建立的模型进行比较。建模工作将提供关于传统两相流模型的局限性的信息以及对He II输运性质的基本理解。

Abstract Proposal Number: CTS-9806725 Principal Investigator: S. Van Sciver Helium II, or superfluid helium, is a unique fluid existing below 2.2K. Among other properties, He II has an extremely high heat conductivity and obeys a non-linear heat equation. This property has encouraged the use of He II in a number of technical devices including superconducting magnets and spaced based instruments. To date, most work on He II focussed on studies of heat and mass transport in the single phase fluid with emphasis on steady state and transient heat transfer in static and forced flow. In the proposed work, this will be expanded to include coexisting He II/saturated vapor while in a horizontal flow. A horizontal experimental test facility will be developed to measure the effects of vapor quality, void fraction, mass flow, and heat transfer rates. Experimental results will be compared to models developed based on the fundamental properties of the He II and the vapor. The modeling effort will provide information on the limits to conventional two phase flow models and the basic understanding of the transport properties of He II.