Sensitivity Analysis for Thermophysical Property Measurements Using the Periodic Method

Abstract

The frequency domain provides an interesting alternative platform for measuring thermophysical properties. The resulting measurement technique produces reasonably accurate thermophysical data from imprecise surface information. Having a periodic heat flux input at one surface, the thermal diffusivity is obtainable if temperature produces a measurable periodic effect at another location. The analysis shows that only the phase shift is necessary to produce needed information while the boundary conditions can affect the experimental results. This method was tested near room temperature using two different materials: Delrin and 304 stainless steel. The experiments yield accurate thermal diffusivity data for both materials but the data for Delrin exhibit smaller errors. Before performing the experiments, a sensitivity analysis was carried out to determine the best range of frequencies for an experimental investigation.