Development, validation, and comparison of FE modeling and ANN model for mixed-mode solar drying of potato cylinders

This work aims to develop a finite element (FE) model for predicting temperature and moisture ratio of potato cylinders having diameters of 8, 10, 13 mm and 50 mm length during solar drying using COMSOL Multiphysics software. The developed model computed conduction, convection, and radiation with appropriate governing and boundary conditions by coupling heat transfer in solid, laminar flow, transport of diluted species, and moving mesh modules together. Moving mesh module was employed to embrace the effect of inevitable shrinkage parameter all through solar drying. Experimentations and calculations were done based on the requirement of FE model. The developed model showed the increment of product temperature from 299.51-313.73 K, 299.07-313.03 K, and 298.34-314.57 K in case of 8, 10, and 13 mm diameter samples for an effective drying period of 3 h 15 min, 4 h 15 min, and 5 h, respectively. At the same time, the moisture content reduced from 83.57%, 86.57%, and 82.12% (wb) to 9.08%, 9.99%, 10.44% (wb) for the respective samples. To prove the reliability of the FE model predicted results, an attempt was made through the artificial neural network (ANN) model for describing the drying performance of the potato as well. It was found that the FE model better simulated the drying behavior with higher R² values (R²  = 0.988-0.995). The drying chamber air temperature was also simulated from FE model and validated with experimental data during drying of samples. The prediction capability of FE proposed model based on statistical error analysis showed lower values than ANN model. PRACTICAL APPLICATION: In the present study, the potential of mixed-mode solar drying in food processing industries was established showing detailed investigation of transport processes throughout the solar drying process of potato cylinders. The established finite element (FE) model can be considered as a realistic alternative to experimentation. The food processing industries and dryer engineers can achieve better quality dried products by precisely operating the dryers at the optimum condition by help of the proposed FE model and product shrinkage analysis.