Heat Flux Estimation using Simplified Models by means of Deviation Time

Most of the thermal problems in engineering involve transient three-dimensional models of complex numerical or analytical solution. In some cases, the three-dimensional problems can be reduced. The use of simplified models to the inverse problem's solution has some advantages, such as: reduction in computational time and disregard some boundary conditions (convection heat transfer coefficient or prescribed temperature). To the procedure presentation, some heat fluxes were simulated in one-dimensional finite models. The Transfer Function Based on Green's Functions (TFBGF) method was used as inverse problem solution tool and excellent estimates were realized using the semi-infinite model. In a controlled laboratory experimental test, this procedure of model reduction was also applied. The heat flux was successfully estimated by using two different models: an 1D semi-infinite and an 1D finite. These simplifications are only valid for times shorter than deviation time.