Simulation Analysis of the Freezing Process For Achieving Bidirectional Freezing Coating Via the Freeze-Casting Technique

Abstract

To delve deeper into the shapes and positions of the solidification front, as well as the detailed temperature distributions under various solidification conditions, this study employed the commercial software ANSYS FLUENT to conduct a meticulous numerical simulation of the two-dimensional solidification process in freeze casting. As part of the research, the enthalpy-porous media solidification/melting model was chosen as the core theoretical framework, and the accuracy of the numerical calculations was verified by comparing them with locally measured temperature changes from experiments. Subsequently, we further examined the influence mechanisms of factors such as cold source temperature, solid content, mold depth, and mold thermal conductivity on the speed of the solidification front. This is crucial because, in the freeze casting process, the speed of the solidification front directly determines the formation and evolution of macropore structures. The results of the simulation analysis indicate that an increase in mold thermal conductivity, a decrease in cold source temperature, a shallower mold depth, and a higher solid content all lead to a corresponding increase in the movement speed of the solidification front. These simulation outcomes not only provide strong theoretical support for optimizing the process parameters of freeze casting but also aid in achieving more precise control over the microstructure of materials, thus enabling a more efficient and accurate material preparation process.