Inverse convection in a flat mini-channel: towards estimation of fluid bulk temperature distribution with infrared thermography

This study deals with the solution of an inverse problem in a flat mini-channel of of 1 mm thickness. At this scale, the difficulty is to introduce non-intrusive sensors. The sensors can modify the local flow and therefore the heat transfer. Our objective is to characterize the mean velocity U and the heat transfer coefficient of external exchange h in order to recover the bulk temperature distribution Tb(x). The inverse method makes it possible to go back to this information starting from measurement of the temperature fields on the two external faces of the channel and from a corresponding model through the minimization of a least square criterion. In this work, the temperature fields can be obtained either by a numerical model or by infrared thermography. Before an experimental validation by infrared thermography, we perform numerical simulations and a sensitivity analysis of the external temperature fields to the mean flow velocity U and to the external heat transfer coefficient h. The temperature and flux distributions over the internal faces of the walls are estimated by an inverse method then.