Carvalho Igor S, Cotta Renato M, Naveira-Cotta Carolina P, Tiwari Manish K
Petrobras S.A., Rio de Janeiro, Brazil.
Laboratory of Nano and Microfluidics and Microsystems, LabMEMS, Mechanical Engineering Department, POLI and COPPE, UFRJ, Federal University of Rio de Janeiro, Brazil.
Proc Math Phys Eng Sci. 2021 Apr;477(2248):20200874. doi: 10.1098/rspa.2020.0874. Epub 2021 Apr 28.
The freezing phenomena in supercooled liquid droplets are important for many engineering applications. For instance, a theoretical model of this phenomenon can offer insights for tailoring surface coatings and for achieving icephobicity to reduce ice adhesion and accretion. In this work, a mathematical model and hybrid numerical-analytical solutions are developed for the freezing of a supercooled droplet immersed in a cold air stream, subjected to the three main transport phenomena at the interface between the droplet and the surroundings: convective heat transfer, convective mass transfer and thermal radiation. Error-controlled hybrid solutions are obtained through the extension of the generalized integral transform technique to the transient partial differential formulation of this moving boundary heat transfer problem. The nonlinear boundary condition for the interface temperature is directly accounted for by the choice of a nonlinear eigenfunction expansion base. Also, the nonlinear equation of motion for the freezing front is solved together with the ordinary differential system for the integral transformed temperatures. After comparisons of the solution with previously reported numerical and experimental results, the influence of the related physical parameters on the droplet temperatures and freezing time is critically analysed.
过冷液滴中的冻结现象对许多工程应用都很重要。例如,这种现象的理论模型可以为定制表面涂层以及实现疏冰性以减少冰的附着力和积聚提供见解。在这项工作中,针对浸没在冷空气流中的过冷液滴的冻结现象,开发了一个数学模型和混合数值 - 解析解,该过程涉及液滴与周围环境界面处的三种主要传输现象:对流换热、对流质传递和热辐射。通过将广义积分变换技术扩展到这个移动边界传热问题的瞬态偏微分方程,得到了误差可控的混合解。通过选择非线性特征函数展开基,直接考虑了界面温度的非线性边界条件。此外,冻结前沿的非线性运动方程与积分变换温度的常微分方程组一起求解。在将解与先前报道的数值和实验结果进行比较之后,对相关物理参数对液滴温度和冻结时间的影响进行了严格分析。