Convective drying performance of porous moist objects under turbulent flow conditions: effects of object shape and material

Purpose The purpose of this paper is to examine the coupled heat and mass transport of different shaped porous moist objects in a rectangular channel under the effects of convective drying. Numerical simulations were performed under turbulent conditions for cylindrical, triangular and rectangular shaped different food products in a two-dimensional channel. Design/methodology/approach Finite element method was used for the unsteady problem and, effects of drying air velocity (AV) and temperature on transport mechanism were evaluated. Three different food materials were used for the circular shaped object and drying performance of the products under different conditions was compared. Findings Results showed that, changing the air temperature has an important effect on drying for all shaped objects and all materials. The same effect was seen for the AV as, increasing the velocity had positive effects on drying. Two identical objects were placed in the channel one behind the other, and this configuration showed that location of the object in the channel is also important for drying. The moisture content in the object at the front is lower than in the object behind at the end of drying. Originality/value This paper can provide technical support to optimize drying performance in the industry with comprehensive data for the process.

Thermal and solutal transport analysis in swirling flow of Maxwell fluid subject to Cattaneo–Christov theory

In this article, the thermal and solutal analysis are carried out in the swirling flow of Maxwell fluid over a stretchable rotating cylinder in the perspective of Cattaneo–Christov double diffusion theory instead of classical Fourier’s and Fick’s law for heat and mass transport phenomena. The constant rotation of the cylinder and axial-dependent stretching produced the flow under the influence of the magnetic field. The heat sink/source and chemical reaction in flow work as a controlling agent for energy transportation. The problem of thermal and solutal transport in flow under certain suppositions is modeled in the form of partial differential equations. Furthermore, the partial differential equations are converted to ordinary differential equations using flow similarities. To calculate the numerical computation of similar ordinary differential equations is performed through the bvp4c MATLAB technique. The flow phenomenon and energy distribution in flow are examined by using graphs. The key findings of this study reveal that increase in relaxation time parameters for heat and mass transport, both temperature and concentration profiles decline. Moreover, the energy transport increases for the higher heat source and chemical reaction parameters.

Numerical simulation for heat and mass transport analysis for magnetic-nanofluids flow through stretchable convergent/divergent channels

This paper adopts a theoretical approach to explore the heat and mass transport features for MHD Jeffery–Hamel flow of viscous nanofluids through convergent/divergent channels with stretching or shrinking walls. Recently, this type of flows generated by nonparallel inclined plates with converging or diverging properties has been frequently utilized in various industrial and engineering processes, like, blood flow through arteries, different cavity flows and flow through canals. The current flow model is formulated mathematically in terms of partial differential equations (PDEs) in accordance with conservation laws under an assumption that the flow is symmetric and purely radial. In addition, heat and mass transport mechanisms are being modeled in the presence of Brownian motion and thermophoretic aspects using Buongiorno’s nanofluid model. The dimensionless variables are employed to get the non-dimensional forms of the governing PDEs. The built-in MATLAB routine bvpc4 is implemented to determine the numerical solutions for governing the nonlinear system of ordinary differential equations (ODEs). Numerical results are presented in the form of velocity, temperature and concentration plots to visualize the influence of active flow parameters. The simulated results revealed that the Reynold number has an opposite effect on dimensionless velocity profiles in the case of convergent and divergent channels. Besides, the temperature distributions enhance for higher values of Brownian motion parameter.