Annular-Mist Flow Transport With Phase Change in Complex Fin-Matrix Passages

复杂翅片基质通道中相变的环形雾流传输

• 批准号: 9024862
• 负责人: Van Carey
• 金额: $ 27.49万
• 依托单位: University of California-Berkeley
• 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: 1991-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9024862&HistoricalAwards=false
• 关键词: Annular; Mist; Flow; Transport; Phase

The present capability to understand and predict two-phase transport for annular flow in complex fin-matrix passages is clearly limited by the current lack of information regarding the shedding, entrainment and deposition mechanisms in such flows. These studies address this problem specifically by examining the manner in which liquid is shed from fin structures and the way in which the liquid breaks-up into droplets and is dispersed into the core flow. Microprobe instrumentation is being developed to obtain quantitative information about local droplet density and size distribution downstream of fin structures, and this instrumentation will also augment the general capabilities of researchers working on multiphase flow transport. Detailed quantitative measurements of the entrainment downstream of fin-type structures and lateral transport of liquid between fins and prime surface areas, as well as in situ measurements in vaporizing and condensing flows in fin matrix passages are being made. These experiments include simultaneous measurement of entrainment characteristics and overall heat transfer for convective vaporization and condensation of pure coolants and binary mixtures over wide ranges of flow conditions. The final stage of the study will use data obtained in the experiments to assess and improve existing models of shedding, deposition and lateral film transport. These improved models will be incorporated into improved computational schemes for predicting the overall transport to evaluate the impact of these mechanisms on heat and mass transfer in the matrix. The information regarding liquid transport mechanisms obtained in the proposed research will serve to enhance the capabilities for predicting two-phase transport in compact evaporators and condensers, cooling towers, and other equipment in which the flow passages are complex and/or contain interrupted surfaces.

目前理解和预测两阶段的能力 在复杂的翅片-基体通道中， 由于目前缺乏有关信息， 在这种情况下，脱落、夹带和沉积机制 流动。 这些研究通过以下方式具体解决了这一问题： 检查液体从鳍上脱落的方式 结构和液体分解成 液滴并分散到核心流中。 微探针 正在开发仪器以获得定量的 关于局部液滴密度和尺寸分布信息 鳍结构的下游，该仪器将 也增强了研究人员的一般能力， 关于多相流传输的。 详细的定量 翅片下游卷吸量测量 结构和鳍片之间的液体横向输送， 主要表面积，以及现场测量， 翅片矩阵通道中的蒸发和冷凝流， 正在制作。 这些实验包括同时 卷吸特性和总热量测量 对流蒸发和冷凝的传递 冷却剂和二元混合物在宽流量范围内 条件 研究的最后阶段将使用数据 在实验中获得，以评估和改善现有的 脱落、沉积和横向薄膜传输模型。 这些改进的模型将被纳入改进的 计算方案，用于预测整体运输， 评估这些机制对热量和质量的影响 转移到矩阵中。 关于液体的信息 在拟议的研究中获得的运输机制将 有助于提高预测两相的能力 在紧凑型蒸发器和冷凝器中运输，冷却 塔和其他设备，其中流动通道 复杂和/或包含中断的表面。