SENSITIVITY ANALYSIS WITH RESPECT TO THE SURFACE HEAT-TRANSFER COEFFICIENT AS APPLIED TO THERMAL-PROCESS CALCULATIONS

A new method is presented to compute the sensitivity of the temperatur e course inside conduction heated foods with respect to the surface he at transfer coefficient. The method is based on the finite element for mulation of the heat conduction equation. As an illustrative example, a sensitivity analysis of the reheating process of ready-made lasagna is carried out. Sensitivity charts are constructed which relate the di mensionless centre temperature with the Blot and Fourier number for sl ab, cylinder and sphere shapes. It is shown that in the case of proces ses with low surface heat transfer coefficient, such as food chilling using air at moderate speeds or convection heating of prepared meals, small deviations in the surface heat transfer coefficient may result i n large deviations in the core temperature of the food.