DETERMINATION OF CONVECTIVE HEAT-TRANSFER COEFFICIENTS USING 2D MRI TEMPERATURE MAPPING AND FINITE-ELEMENT MODELING

Finite element modeling was used in combination with 2D MRI temperatur e mapping to calculate fluid to particle convective heat transfer coef ficients (h(fp)) across the surfaces of a carrot particle being heated with 80 degrees C water with an average velocity of 4.4 cm/s. Heat tr ansfer in the region of interest (image acquired from center of sample ) was essentially two-dimensional because of the length of the carrot sliver The h(fp) at each surface was determined by trial and error mat ching of temperature contours in the model to those in the MRI image. Calculated values of h(fp), (117-389 W/m(2) K) were within the range o f those reported in the literature. The major advantages of this metho d are that the actual shape of the food particle is used in the model, and it can be utilized in applications where the particle does nor he ar uniformly from all directions. (C) 1998 Elsevier Science Limited Al l rights reserved.