Influence of viscosity on the thermal behavior of fluids in a sealed can

Abstract

Homogeneous fruit juice in a sealed container available in the commercial market exhibits some degree of non-Newtonian behavior with a wide viscosity range. During thermal processing, it is necessary to understand the effect of viscosity on thermal behavior, which may guide insight into the choice of physics involved in the conservation law equations. In this context, the present study considered the Carboxyl Methyl Cellulose (CMC) solutions (a viscosity-enhancing agent) as model foodstuffs to understand the effect of viscosity on the heat transfer mechanism in the thermal treatment of canned liquid products. Computational Fluid Dynamics (CFD) was employed to analyze the thermal behavior of different concentrations of CMC solutions, estimated based on averaged wall heat flux, averaged heat transfer coefficient, volume-averaged temperature, and minimum temperature. The effect of the CMC solutions' rheological properties on the thermal behavior was evaluated by comparing it with the pure conduction simulations. The time–temperature history obtained from the simulations was coupled with the kinetic parameter of microbial destruction to predict the heating time. When the viscosity increases due to increasing the concentration of CMC solution, the natural convection is suppressed, which leads to the heat transfer in almost pure conduction mode.

Keywords

• Thermal treatment
• Heat transfer behavior
• Natural convection
• CFD
• Lethality
• Heating time