Advanced thermal simulation of processes involving materials exhibiting fine-scale microstructures

Image-based simulation is being considered more and more in industrial applications, where more than simulate the expected reality it seems preferable to simulate the reality itself. For example, in heterogeneous composite materials more than assuming a particular distribution of the material constituents, it is preferable to solve the model in the real distribution, the one existing in the considered material that is accessible from an appropriate scanning technique. However such route requires, in many applications, advanced simulation techniques able to proceed in real time, looking for a synchronism with the scanning process itself. This constitutes a challenging issue due to the rate of image acquisition and the amount of information associated to each one. This work proposes an efficient strategy for solving thermal problems in two scales heterogeneous media in both the linear and the nonlinear case. In both cases the calculation of the homogenized thermal conductivity tensor requires the solution of many thermal problems defined at the microstructure level, here considered coming from digital images. For alleviating the computational cost and speeding up calculations to fulfill real time constraints, we propose an offline/online procedure for evaluating the homogenized thermal conductivities.