Simulation of supercooling and size distribution in frazil ice dynamics
Simulation of supercooling and size distribution in frazil ice dynamics
复制标题
碎冰动力学中过冷度和尺寸分布的模拟
DOI：
10.1016/0165-232x(94)90001-9
复制
发表时间：
1994
影响因子：
4.1
通讯作者：
A. Omstedt
中科院分区：
文献类型：
--
作者：
U. Svensson;A. Omstedt
这项工作的目的是制定碎冰动力学的数学描述。该公式应与物理过程（例如二次成核）的当前知识相平衡。由于其中一些过程的知识是零散的，这意味着需要寻求概念上简单的表述。已知许多过程会影响过冷速率和碎冰产量。本配方考虑了以下过程：初始晶种、二次成核、重力去除、由于水体积冷却而增长以及絮凝/破碎。为这些过程制定方程时考虑了时间和粒子半径的分辨率，但不考虑空间（充分混合的罐子）。使用简单的显式数值方案求解方程。初步结果表明可以校准模型以描述文献中报告的实验结果。主要用于比较的是过冷曲线，但也考虑了有关晶体尺寸分布的一些信息。值得注意的是，由于缺乏对某些物理过程的详细数学描述，该模型经过校准以适应实验。还使用敏感性分析来确定模型的行为符合实验结果和预期。该研究的主要结论是可以制定和校准一个相当简单的数学模型，该模型符合迄今为止文献中报道的实验数据。进一步得出的结论是，径向空间中的分辨率可以提供对过程动力学的额外了解。尺寸分布的演变及其对播种和消散率的敏感性已经被预测，结果看起来物理上合理。
The objective of the work presented is to formulate a mathematical description of frazil ice dynamics. The formulation is to be in balance with the current knowledge of the physical processes, for example secondary nucleation. As the knowledge of some of these processes is fragmentary, this means that a conceptually simple formulation is sought. A number of processes are known to influence the supercooling rate and the frazil ice production. The present formulation accounts for the following processes: initial seeding, secondary nucleation, gravitational removal, growth due to cooling of water volume and flocculation/break up. Equations are formulated for these processes considering a resolution in time and radius of particles but not in space (well-mixed jar). The equations are solved using a simple explicit numerical scheme.Preliminary results indicate that the model can be calibrated to describe the experimental results reported in the literature. It is mainly the supercooling curves that are used for comparison but some information about the crystal size distribution is also considered. It is to be noted that the model is calibrated to fit the experiments, due to the lack of detailed mathematical description of some of the physical processes. Sensitivity analysis is also used in order to establish that the model behaves according to experimental findings and expectations. The main conclusion of the study is that a fairly simple mathematical model can be formulated and calibrated, which fits the experimental data reported in the literature hitherto. It is further concluded that a resolution in radial space gives additional insight into the dynamics of the process. The evolution of the size distribution and its sensitivity to seeding and dissipation rate has been predicted with results that look physically plausible.