Drying of Wheat Based on the Non-Equilibrium Thermodynamics: A Numerical Study

Diffusion Models to Describe the Drying Process of Peeled Bananas: Optimization and Simulation

“…Among the available methods, the finite volume method is commonly used. [14,20] For example, Carmo and Lima [21] used this method and employed a fully implicit formulation to describe mass transfer inside a lentil kernel during the drying process. In this work, the authors used generalized coordinates due to the irregular shape of the grain, and they considered the variable diffusivity as a function of the average moisture content.…”

“…[6][7][8][9][10][11][12][13][14][15] To use liquid diffusion models, normally two conditions must be satisfied: (1) external transfer processes do not present any limiting operations and (2) internal heat transfer is much more rapid than mass transfer. In order to use a diffusive model, the diffusion equation must be solved.…”

Convective Drying Analysis of a Single Wheat Kernel Based on an Irreversible Thermodynamics Model

“…This hypothesis was investigated in this work, since it may have caused an over-or underestimation of the liquid and vapor conductivities in addition to the temperature and moisture content profiles with higher slopes. Fortes et al's [1] approach was used by Oliveira and Lima, [20] who numerically analyzed the simultaneous heat and mass (liquid and vapor) transport in bodies of ellipsoidal shape or, more precisely, prolate spheroids, such as the wheat kernel. The numerical solution of Oliveira and Lima, [20] using prolate spheroidal coordinates and the finite volume method, was consistent when applied to one drying condition.…”

“…Fortes et al's [1] approach was used by Oliveira and Lima, [20] who numerically analyzed the simultaneous heat and mass (liquid and vapor) transport in bodies of ellipsoidal shape or, more precisely, prolate spheroids, such as the wheat kernel. The numerical solution of Oliveira and Lima, [20] using prolate spheroidal coordinates and the finite volume method, was consistent when applied to one drying condition. However, the authors did not verify the validity of their method when applied to the entire range of drying data reported by Fortes et al [1] The works of Ghosh et al [13] and Gong et al [15] presented simple models that were applied to just one or two drying conditions.…”

“…The main thin-layer theoretical models are included mechanistic models, such as liquid diffusion models and=or vapor diffusion, [6][7][8][9][10][11][12][13][14][15] statistical models and models derived from the thermodynamics of irreversible processes and=or mixed models. [1,[16][17][18][19][20] Durst, [21] based on literature data, pointed out that the kinetic theory of gases provided excellent qualitative descriptions of drying processes, but led to inaccurate prediction of the quantitative aspects such as temperature jumps. The statistical rate theory utilized the transition probability concept and did not adequately predict the energy flux.…”