Numerical analysis of cellulose nanocrystals CNC for reducing cold damage to reproductive buds in fruit crops

Abstract

Computational fluid dynamics (CFD) modeling of transient heat transfer was performed using ANSYS Fluent during the freezing process of buds treated with cellulose nanocrystal (CNC) to better understand the thermal behavior of CNC and the mechanism by which it provides cold damage protection. The numerical model developed were able to predict the temperature transition and the time required for the bud ice nucleation: the ice nucleation for the control bud started around 1080 s at about 270.2°K (−2.95 °C), while the ice nucleation for the CNC treated bud started around 1450 s at about 268°K (−5.15 °C). The CNC reduced the heat loss due to outgoing radiation to the external environment and decreased the heat flow loss due to convection heat transfer. As a result, CNC delays the formation of intracellular ice at low temperatures and protecting cold damage. The CFD simulation results of temperature distribution profiles were compared with the experimental data, yielding an average relative error of less than 15%. CFD model was able to estimate the convection heat flow, radiation heat transfer, and latent heat (phase change), all of which are difficult to investigate by making measurements in lab conditions.