Estimation of heat flux in bread baking by inverse problem

Inverse heat techniques have been employed to evaluate the unknown parameters such as heat transfer coefficient, thermal properties, mass diffusivity, and to estimate boundary conditions by utilizing the temperature measurement within the solid material. These parameters with direct measurements are difficult, or sometimes even impossible. The heat flux is one of the essential parameters which would provide information about baking performance and the quality of the product. Generally, direct measurement of heat flux with sensors is difficult under unsteady state conditions. Therefore, in the present investigation, heat flux was estimated with simple temperature data during bread baking by the inverse method at a temperature of 200 degrees C under natural and forced convections with and without deformation. The Levenberg-Marquardt algorithm was chosen for the solution of the inverse problem. The predicted temperatures at the desired location were obtained by a direct method in COMSOL Multiphysics, and these were validated with experimental temperature data for the efficacy of the inverse problem. The convective, radiative heat flux, and heat transfer coefficient were also computed from the obtained heat flux data. The obtained results in this investigation were well correlated with findings reported in the literature.