A new modification of the Angstroem’s method for thermal diffusivity measurement has been developed. This relies on the propagation of harmonic thermal waves with mean value equal to the ambient temperature. The diffusivity is evaluated by relatively simple processing of temperature data, acquired by infrared thermography.The evaluation is based on a mathematical model, in which the heat transfer coefficient at the specimen surface is assumed to be constant. This work is aimed at verifying that assumption. In particular, the effects of natural convection in air are investigated theoretically by numerical simulation. A strategy to improve the test procedure is finally outlined.
Analysis of the impact of surface heat transfer on a new modification of the Angstroem’s method / C., Bussi; Corticelli, Mauro Alessandro; Muscio, Alberto. - STAMPA. - (2004), pp. G.5.1-G.5.6. (Intervento presentato al convegno QIRT 2004 - 7th International Conference on Quantitative Infrared Thermography tenutosi a Rhode-St-Genèse (Bruxelles), Belgium nel 5-7 giugno 2004).