Numerical Study of a Non-Linear Porous Sublimation Problem With Temperature-Dependent Thermal Conductivity and Concentration-Dependent Mass Diffusivity

Abstract

Sublimation heat transfer occurs in a wide range of engineering processes such as Accelerated Freeze Drying, energy storage and food technology. Particularly, in microwave AFD process, preservation of material with least possible energy consumption is desirable. In connection with this, it is of interest to analyze the effect of temperature/concentration dependent heat/mass transfer properties. Given the limited literature available on sublimation, there is a general lack of physical understanding of this particular problem. The present work analyses non-linear sublimation process driven by convective heat/mass transfer and evaporation of water vapor using the Legendre wavelet-collocation method. Results from the present work are shown to be in excellent agreement with the exact solution of special case of a linear problem. Further, present numerical technique shows strong acceptance with finite-difference method in case of full non-linear model. The model is used for a comprehensive investigation of the impact of problem parameters appearing in this study on the rate of sublimation. It is found that sublimation rate increases with increasing values of ß1 and decreasing values of ß2. The impact of other dimensionless problem parameters such as Peclet numbers Pe1 and Pem, convection due to moisture flow of water vapor ß, latent heat of sublimation l0 and Luikov number Lu on sublimation process is also discussed in detail. These observations offer a comprehensive theoretical and mathematical understanding of sublimation heat/mass transfer under practical conditions for improving the performance and efficiency of freeze-drying related engineering processes.

Use of Freeze Drying in Fruit and Vegetables: Review

“…In the sublimation process, the solutes are spatially arranged according to the original structure. Differently, in common drying, the solutes are concentrated, even after the process (Chaurasiya et al, 2023). Sublimation is an endothermic phenomenon, that is, heat must be supplied to the system, which can be obtained by conduction, radiation or combined (convection/radiation and conduction/radiation) (Chang et al, 2023).…”

“…When sublimating, water vapor molecules carry a significant amount of latent heat (heat necessary for phase change), and the temperature of the frozen product is reduced. If there is no heat source donated to the process, the applied pressure may end up equaling the vapor pressure of the contained solvent; if this happens, the product will not immediately pass into the gaseous phase, but rather into the liquid phase (Chaurasiya et al, 2023).…”

“…This step is responsible for removing 80 to 90% of the moisture present in the food. If there is a failure in the process and there is water in liquid form, the product may form bubbles and its appearance will be compromised (Chaurasiya et al, 2023).…”

Simulation of the Effect of Air Humidity Ratio in the Drying Room on the Rate of Material Evaporation in Vacuum Freeze Drying

“…The results of convective heat and mass transfer studies with volumetric heating show that the sublimation rate increases with volumetric heating sources [19]. Chaurasiya et al, [20] conducted research in the case of non-linear porous sublimation where thermal conductivity depends on temperature and mass diffusivity depends on concentration. The research results provide a complete theoretical and mathematical understanding.…”

Fast Calculation of Supercritical Carbon Dioxide Flow, Heat Transfer Performance, and Mass Flow Rate Matching Optimization of Printed Circuit Heat Exchangers Used as Recuperators

“…Its flow and heat transfer characteristics are mainly affected by channel structure, fluid property, and operating parameters. Theoretical analysis [13], experimental tests [14,15], numerical simulation [16,17], and other methods are commonly used to study heat exchangers. Some scholars use three-dimensional numerical simulation methods to conduct the calculation of straight channel [18][19][20][21], Zigzag channel [22][23][24][25], S-shaped fins channel [26][27][28][29], and airfoil fins channel [30][31][32][33] structures and obtained detailed temperature and velocity fields.…”