TY  - EJOU
AU  - Cao, Xuewen 
AU  - Chen, Zhe 
AU  - Ding, Gaoya 
AU  - You, Wei 

TI  - Coupled Modeling of CO<sub>2</sub> Frosting, Fluid Flow, and Heat Transfer under Cryogenic Conditions Using a Nucleation-Based CFD Framework
T2  - Fluid Dynamics \& Materials Processing

PY  - 2026
VL  - 22
IS  - 7
SN  - 1555-2578

AB  - A two-dimensional Computational Fluid Dynamics (CFD) model, grounded in classical nucleation theory, is developed to investigate CO<sub>2</sub> frosting and the associated heat transfer under cryogenic conditions. The model integrates gas–solid phase-change kinetics with multiphysics transport equations to capture the coupled phenomena governing frost formation. The Peng–Robinson equation of state is employed to predict CO<sub>2</sub> frost points in binary mixtures, with model predictions validated against experimental data, yielding errors in frost thickness and thermal conductivity below 15%. The results demonstrate that decreasing the cryogenic wall temperature from 160 K to 150 K increases the average frost thickness and density by 57% and 78%, respectively, while advancing the peak in thermal resistance by approximately 5 min. A reduction in CO<sub>2</sub> mol fraction from 10% to 6% leads to an 82% decrease in average frost density. Although inlet velocity exerts a limited influence on frost density, excessively high velocities increase porosity and inhibit densification. Flow field analysis reveals that progressive frost growth constricts the effective channel area, resulting in a local velocity increase of approximately 23%. Moreover, the spatial distributions of supersaturation and nucleation rate exhibit strong consistency. These findings elucidate the complex coupling between CO<sub>2</sub> frosting, fluid flow, and heat transfer in Pressurized Liquefied Natural Gas (PLNG) systems, offering theoretical insights for optimizing low-energy CO<sub>2</sub> cryogenic capture and enhancing natural gas liquefaction processes.
KW  - PLNG; CO<sub>2</sub> frosting; model of nucleation; cryogenic heat exchange; CFD simulation

DO  - 10.32604/fdmp.2026.080209