Analysis of the effects of package design on the rate and uniformity of cooling of stacked pomegranates: Numerical and experimental studies

- Forced-air cooling (FAC) of pomegranate fruit was investigated.
- CFD model was developed, validated and used to analyse the cooling characteristics.
- Stack design markedly affected the airflow profile, rate and uniformity of cooling.
- High and low cooling regions inside the stack were identified and quantified.
- Pattern of high and low temperature regions depended on package design.

Computational fluid dynamics (CFD) model was developed, validated and used to analyse cooling characteristics of two different package designs (CT1 and CT2) used for postharvest handling of pomegranate fruit. The model incorporated geometries of fruits, packaging box, tray and plastic liner. Thin layer of plastic material with conservative interface heat flux was used to model liners. The accuracy of the model to predict airflow and temperature distributions were validated against experimental data. The model predicted airflow through the stacks and cooling rates within experimental error. Stack design markedly affected the airflow profile, rate and uniformity of cooling. The cooling rate of the two package designs differed by 30% and plastic lining increased the average 7/8th cooling times from 4.0 and 2.5 h to 9.5 and 8.0 h for the CT1 and CT2 stacks, respectively. Profile of high and low temperature regions depended considerably on packaging box design.