ESTIMATION OF UNKNOWN-PARAMETERS FROM EXPONENTIAL HEATING OF A LAMINAR-FLOW

The forced convection of a fluid flowing in a circular duct, in the re gion upstream of a heating section, is analyzed by means of an experim ental apparatus designed, built, and used specifically for this. A wid e range of laminar Reynolds numbers (150 less than or equal to Re less than or equal to 1000) and heating rates were covered in the experime ntal study. The experiments, carried out with a fully developed veloci ty profile, show the wall temperature growing exponentially in the dir ection of flow. The experimental data are reduced in order to evaluate the exponent of the wall temperature and the Nusselt number distribut ion along the duct. Furthermore, the strong dependence shown by the ch aracteristic thermal parameters suggests that this experimental arrang ement may be used for the estimation of unknown parameters such as the thermal conductivity of the wall and the mass flow rate.