Thermal properties determination of a cylindrical product during its cooling: two-dimensional numerical model and uncertainty

• Main Authors: Wilton Pereira da Silva, Cleide Maria D. P. S. e Silva, Leidjane Matos De Souto, Josivanda Palmeira Gomes, Alexandre J. M. Queiroz, Rossana M. F. De Figueiredo
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2019-01-01
• Series: International Journal of Food Properties
• Subjects: thermal diffusivity; convective heat transfer coefficient; uncertainties; covariance matrix; numerical solution; cooling
• Online Access: http://dx.doi.org/10.1080/10942912.2019.1578791
• ISSN: 1094-2912; 1532-2386

In this article, a two-dimensional model is proposed to determine thermal diffusivity and convective heat transfer coefficient, providing the average values, their uncertainties and the covariance matrix referring to these parameters for a product with cylindrical geometry during its cooling. The proposed model used a two-dimensional numerical solution of the diffusion equation for the direct problem; an experimental dataset referring to the cooling kinetics in the center of the product and an optimizer program based on the Levenberg-Marquardt algorithm for the inverse problem. The model was used with success to determine the thermal properties, their uncertainties and the covariance matrix of a cucumber during its cooling. The obtained results allowed establishing a confidence band that made it possible to graphically evaluate the precision of a new simulation for a cucumber with different dimensions.