Maziukienė Monika, Striūgas Nerijus, Vorotinskienė Lina, Skvorčinskienė Raminta, Urbonavičius Marius
Lithuanian Energy Institute, Laboratory of Combustion Processes, Breslaujos 3, LT-44403 Kaunas, Lithuania.
Lithuanian Energy Institute, Centre for Hydrogen Technologies, Breslaujos 3, LT-44403 Kaunas, Lithuania.
Materials (Basel). 2024 Jul 25;17(15):3687. doi: 10.3390/ma17153687.
Experiments on specimen cooling dynamics and possible film boiling around a body are very important in various industrial applications, such as nucleate boiling, to decrease drag reduction or achieve better surface properties in coating technologies. The objective of this study was to investigate the interaction between the heat transfer processes and cooling dynamics of a sample in different boundary conditions. This article presents new experimental data on specimens coated with Al-TiO film and Leidenfrost phenomenon (LP) formation on the film's surface. Furthermore, this manuscript presents numerical heat and mass transfer parameter results. The comparative analysis of new experiments on Al-TiO film specimens and other coatings such as polished aluminium, Al-MgO, Al-MgH and Al-TiH provides further detail on oxide and hydride materials. In the experimental cooling dynamics experiments, specimens were heated up to 450 °C, while the sub-cooling water temperatures were 14*‒20 °C (room temperature), 40 °C and 60 °C. The specimens' cooling dynamics were calculated by applying Newton's cooling law, and heat transfer was estimated by calculating the heat flux q transferred from the specimens' surface and the Bi parameter. The metadata results from the performed experiments were used to numerically model the cooling dynamics curves for different material specimens. Approximated polynomial equations are proposed for the polished aluminium, Al-TiO, Al-MgO, Al-MgH and Al-TiH materials. The provided comparative analysis makes it possible to see the differences between oxides and hydrides and to choose materials for practical application in the industrial sector. The presented results could also be used in software packages to model heat transfer processes.
在各种工业应用中，如核态沸腾、减少阻力或在涂层技术中实现更好的表面性能，对样品冷却动力学以及物体周围可能出现的膜态沸腾进行实验非常重要。本研究的目的是探究在不同边界条件下样品的传热过程与冷却动力学之间的相互作用。本文给出了涂覆Al-TiO薄膜的样品的新实验数据以及薄膜表面莱顿弗罗斯特现象（LP）的形成情况。此外，本文还给出了传热传质参数的数值结果。对Al-TiO薄膜样品以及其他涂层（如抛光铝、Al-MgO、Al-MgH和Al-TiH）的新实验进行对比分析，进一步详细介绍了氧化物和氢化物材料。在实验冷却动力学实验中，将样品加热到450℃，而过冷水温度为14‒20℃（室温）、40℃和60℃。通过应用牛顿冷却定律计算样品的冷却动力学，并通过计算从样品表面传递的热流q和毕渥数来估算传热。所进行实验的元数据结果用于对不同材料样品的冷却动力学曲线进行数值建模。针对抛光铝、Al-TiO、Al-MgO、Al-MgH和Al-TiH材料提出了近似多项式方程。所提供的对比分析能够看出氧化物和氢化物之间的差异，并为工业领域的实际应用选择材料。所呈现的结果还可用于软件包中对传热过程进行建模。
