Model-free estimation of mass fluxes based on concentration profiles. I. Presentation of the method and of a sensitivity analysis Original Research Article

An approach to identify mass diffusion coefficients (D) is presented, and applied to the case of a slab. It was based on a numerical exploitation of the concentration profiles to estimate the mass fluxes. The effect of the quality of the experimental data (spatial resolution, image, temporal resolution, ΔFo, of the concentration profiles, sampling) on the bias and sensitivity of the method was studied thanks to the use of simulated data (Fo ∈ [0, 2]), to which could be added Gaussian noise. Estimated D value were compared with the true solution (the one used for generating the simulated concentration data). The errors on D are large at low Fo < 0.2. But for Fo > 0.2, D can be estimated with less than 1% of bias if ΔFo < 0.1 and image. Space resolution had a minor effect. Although rough, the numerical procedure adopted in this paper revealed especially suitable for modern techniques of concentration measurements exhibiting high-accuracy (<1%).