Research Initiation Awards: Experimental Investigation of Transient Convective Freezing and Melting of Ice on a Cold Tube Bank in a Crossflow of Water

这项研究是对冻结现象的调查 以及冰在冷管束上的融化。 地铁银行是 浸入流动的水流（T C）和冰 层的研究，生长在外表面上的 当管子内部冷却到冰点以下时， 温度（Tw OoC）。 随后的熔化过程 当冷却剂被移除时，冰的形成也将 研究了 这项研究的主要重点是记录新的 相关性，随时间变化的传热（Nusselt 数量）和流体流量（压降）特性（根据 行）的系统作为冻结和融化过程 收益。 我们将在不同的时间， 精确的冰形轮廓，并将可视化结果 通过管束的流场。 在稳态下， 条件下，局部Nusselt数分布为 得到了 实验将在低至 中等雷诺数范围内，并为一些不同的 冷却温度比。 直列式和交错式管 将考虑几何形状。 管节距的影响 并记录上游湍流水平。 对这项研究的兴趣是有道理的， 从实际出发，从根本上看。 的结果 该研究对热能领域具有重要意义。 存储涉及相变材料。 更 具体而言，本研究中获得的结果将 冰蓄冷设计中的直接工程后果 系统和相变存储热交换器中。 从 从更广泛的角度来看，调查中的问题是一个 相变传热与流体高度复杂耦合 动态问题，解决新的领域，我们目前的 缺乏了解，需要改进。

This research is an investigation of the phenomena of freezing and melting of ice on a cold tube bundle. The tube bank is immersed in a flowing stream of water (T OoC) and the ice layer is studied that grows on the outside surface of the tubes, when the tubes are internally cooled below the freezing temperature (Tw OoC). The subsequent melting process of the ice formations when the coolant is removed will also be studied. The main focus of this research is to document in terms of new correlations, the time-dependent heat transfer (Nusselt number) and fluid flow (pressure drop) characteristics (per row) of the systems as the freezing and melting process proceeds. We will photographically record, at various times, the exact ice shape profiles and will visualize the resulting flow field through the tube bank. Under the steady state condition, the local Nusselt number distribution will be obtained. Experiments will be conducted in the low to moderate Reynolds number range and for a number of different cooling temperature ratios. Both in-line and staggered tube geometries will be considered. The effect of the tube's pitch and the upstream turbulence level will be documented. The interest in this research is justified from both a practical and from a fundamental view-point. The results of the proposed study is important to the field of thermal energy storage involving phase change materials. To be more specific, the findings obtained in this study would have direct engineering consequence in the design of ice storage systems and in phase change storage heat exchangers. From the broader perspective, the problem under investigation is a highly complex coupled phase change heat transfer and fluid dynamic problem that addresses new areas in which our current understanding is lacking and needs improvement.