Heat transfer analysis of canned food sterilization in a still retort

Computational fluid dynamics (CFD) analyses provide insight on the natural convective processes occurring during the sterilization of canned liquid food. The definition and estimation of heat transfer coefficients pertaining to the transient heat transfer occurring in cylindrical food cans is presented. The heat transfer coefficients defined on the basis of absolute mass flow averaged and volume-averaged temperatures are compared. The contributions to the overall heat transfer rate from different surfaces of the uniformly heated cylindrical can are evaluated. The influence of the temperature difference to viscosity ratio on the peculiar Nusselt number trends is discussed. Unified correlations are provided for the Nusselt number as functions of Fourier number, food can aspect ratio and thermal conductivity of the food medium in both the conduction and convection dominated heat transfer regimes.