RSM-CFD modeling for optimizing the apricot water evaporation

In this paper, the response surface methodology is complemented with CFD simulation in order to study the optimization of the drying process of apricot slices. A Box-Behnken design was used. The studied factors were velocity of inlet air (A: 0.1-0.9 m/s), the porosity of apricots (B: 0.4- 0.6%), the temperature of inlet air (C: 20-60℃), and the time of drying process (D: 500- 3500 s). Then COMSOL software v. 4.1 was used to simulate the 25 runs derived from RSM design. The results showed the moisture content of samples in lower tray samples (L1-L5) was significantly (p < 0.01) higher than the upper tray samples (U1-U2). The uniformity of inlet air and temperature distribution has a great effect on the final quality of dried samples. Moreover, the inlet air temperature had a significant effect on moisture content. The interaction between the porosity of apricot, the two factors of the inlet air temperature and the drying time had a negative effect on the U-series response. But the best positive interaction effect was due to the air temperature and the drying time. These results show that the final quality is significantly dependent on the drying factors and the uniformity in temperature distribution in the cabinet dryer. The final optimum conditions for apricot drying were 0.6437 for parameter A (Velocity of inlet air), 0.5531 for parameter B (Porosity of apricot), 36.78 for parameter C (temperature of inlet air), and 3233.75 for parameter D (drying time).