Abstract

The influence of the position and number of blocks of salmon in a freezer on its cooling rate was investigated using computational modelling. The conjugate mathematical model included the turbulent heat natural convection in air inside the freezer and the unsteady diffusion with the phase change of water in the salmon meat, located at the bottom, center and at the lower corner of the freezer. Continuity, linear momentum, energy, and k SMALL ELEMENT OF turbulence model equations were solved using the finite volume method, with a non-uniform staggered grid. The results obtained include the unsteady description of streamlines, temperature, cooling rate and Nusselt number in the meat surface. Accurate temperature measurement in meat were found to be in qualitative and quantitative agreement with the results obtained by the numerical simulation. The highest cooling rate calculated was for the food at the lower corner, and the lowest when was located at the center of the freezer. Precise numerical results for predicting the freezing rate and dimensionless heat transfer were calculated with temperature gradients. The conjugate model made it possible to relate the freezing rate with the luminosity of the food to predict the changes in the color of the pieces of salmon.