Optimal design and measurement of the effective thermal conductivity of a powder using a crenel heating excitation

This paper presents an experimental optimal design of a photothermal radiometry method using a crenel heating excitation. This method is used for the determination of the effective thermal conductivity of a powder in imperfect contact with a coating, and in presence of convective heat losses. The parameter identification is performed by the minimization of the ordinary least squares objective function comparing the measured temperatures to the response of a direct model function of thermophysical parameters. The used iterative algorithm is based on the Gauss-Newton method.