Modeling and simulation of heat and mass transfer in an Ethiopian fresh injera drying process

Solomon, Alamrew B.; Fanta, Solomon Workneh; Delele, Mulugeta Admasu; Vanierschot, Maarten

doi:10.1016/j.heliyon.2021.e06201

Cited by 11 publications

(4 citation statements)

References 46 publications

(102 reference statements)

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“…The values at symmetric positions about the center are nearly equal, but in opposite directions. In the initial stages of drying, heat transfer occurs almost exclusively inside the kernels, with little mass transfer (Solomon et al, 2021). So, the temperature gradient rapidly increases in the initial stage and reaches its maximum value.…”

Section: Resultsmentioning

confidence: 99%

Hot‐air drying of corn kernels: Drying kinetics and quality improvement

et al. 2023

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Background and Objectives: During the hot-air drying process of corn kernels, excessive stress can cause cracks to develop. For this reason, it's essential to identify the optimum parameters that can minimize stress during hot-air drying. Findings: In this study, a three-dimensional fitness model was established based on the average geometric size of corn kernels. Additionally, a hot-air drying model was constructed on the basis of heat and mass transfer, stress-strain theory, and conservation law of heat and mass transfer. Simulated calculations of heat and mass transfer were performed to obtain the temperature and moisture gradient distribution. This distribution was then coupled with a stress model to reveal the variation of drying stress. Verification experiments were conducted on the drying model. The results indicated that the temperature and moisture gradient were symmetrically distributed about the geometric center of corn kernels. At symmetrical positions about the geometric center, their sizes were almost equal but their directions are opposite. The thermal stress and moisture gradient stress showed the fact of larger surface but smaller interior of corn kernels. Furthermore, they both increased rapidly in the initial stage and then slowly decreased. The maximum value of thermal stress was 4.57 kPa, and the maximum value of moisture gradient stress was 0.49 MPa.Conclusions: Mass transfer plays a significant role in the hot-air drying process, and cracks can develop as a result of excessive moisture gradient stress.To mitigate these issues, it's important to increase the air humidity in a controlled manner to significantly reduce the total stress. The maximum error in temperature between simulated and experimental results was 8.5%. This suggests that our drying model can be effectively utilized to explore temperature gradient, moisture gradient, and stress distribution of corn kernels.Significance and Novelty: This study provides insights into the mechanism of stress generation that occurs during the hot-air drying process of corn kernels. Our analysis indicates that properly increasing the air humidity can significantly reduce drying stress and consequently prevent the formation of cracks. This ultimately leads to improved product quality and economic value.

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Section: Resultsmentioning

confidence: 99%

Hot‐air drying of corn kernels: Drying kinetics and quality improvement

et al. 2023

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“…Additionally, experimental procedures have several drawbacks, including lengthy cycles, high economic costs, poor efficiency, and operational challenges. Computer simulation is a more practical, adaptable, and easy technique to disclose the hidden characteristics of items during a complicated drying process than the experimental approach [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. The effectiveness of computer modeling in predicting and adjusting process parameters for RF heating has already been shown [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

Simulated and Verification of Mass and Heat Transfer Coupled Model of Jujube Slices Dried by Hot Air Combined with Radio Frequency Heat Treatment at Different Drying Stages

Cao

Yang

Zang

et al. 2023

Foods

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This study investigates the impact of radio frequency (RF) heat treatment on heat and mass transfer during the hot air drying of jujube slices. Experiments were conducted at different drying stages, comparing single-hot air drying with hot air combined with RF treatment. Numerical models using COMSOL Multiphysics® were developed to simulate the process, and the results were compared to validate the models. The maximum difference between the simulated value of the center temperature and the experimental value was 6.9 °C, while the minimum difference was 0.1 °C. The maximum difference in average surface temperature was 1.7 °C, with a minimum of 0.3 °C. The determination coefficient (R2) between the simulated experimental values of HA and the early (E-HA + RF), middle (M-HA + RF), and later (L-HA + RF) groups was 0.964, 0.987, 0.961, and 0.977, respectively. The study demonstrates that RF treatment reduces drying time, enhances internal temperature, promotes consistent heat and mass transfer, and accelerates moisture diffusion in jujube slices. Furthermore, the later the RF treatment is applied, the greater the increase in internal temperature and the faster the decrease in moisture content. This research elucidates the mechanism by which RF heat treatment influences heat transfer in hot air-dried jujube slices.

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“…geothermal reservoirs [3], deep geological repositories for radioactive waste [4], oil reservoirs [5][6][7], food [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], concrete [23][24][25], wood [26], peat [27][28][29], and organic fuels embedded in sand [30][31][32][33][34]. The role of moisture varies significantly among these applications and therefore the approaches and assumptions used to model evaporation and condensation are also different.…”

Section: Introductionmentioning

confidence: 99%

“…In food drying, the removal of moisture reduces microbiological activity (e.g., mold growth), improving food storage and conservation [15,18,21]. Convective drying is typically used, where forced air with low relative humidity is applied at the food surface [9,[11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%