Sensitivity analysis of heat and mass transfer characteristics during forced-air cooling process of peaches on different air-inflow velocities.

Peach is one of the most perishable fruits. During forced-convection cooling, the heat sources (respiratory and evaporative latent heat) internal to freshly harvested peaches have a remarkable influence on its evaluation of cooling characteristics with respect to various cooling strategies. Therefore, to improve the accuracy of simulation results in peaches cooling, the term of heat source was coded as detailed procedures and included into a computational fluid dynamics (CFD) model. By comparing the temperature simulated with and without considering these heat sources, it is found that a reasonable decrease in variations of cooling performances is obtained with sustained increase in air-inflow velocities. A maximum discrepancy in peaches volume-weighted average temperature (∆T vwa-max) is mainly concentrated in 0.1-0.3°C when the air-inflow velocity not exceeds 1.7 m/s, and its corresponded 7/8ths cooling time (SECT) is also prolonged by 1-6 min. This means that, below 1.7 m/s, these heat sources should be added as a term into the heat transfer equations for modifying the mathematical model inside peaches computational domain. Furthermore, the feasibility of this modeling method is confirmed by a great agreement with experiments, and its modified model has a higher accuracy with the decreased RMSE and MAPE values of 6.90%-11.26% and 7.28%-12.95%, respectively.