Determination of the thermal diffusivity of aqueous solutions of methanol in an extended range of temperature by a laser-induced thermal grating technique

Abstract

Experimental thermal diffusivity data are presented for aqueous solutions of methanol in the temperature range 295–335 K. The thermal diffusivity measurements were performed using a laser-induced thermal grating technique at atmospheric pressure. The aqueous solutions studied have weight fractions of 20, 40, 60, and 80% methanol. Because of the small temperature rise (Δ T < 0.2 K) in the thin sample (sample thickness d = 0.5 mm) during the measurements and the very short measuring time of a few milliseconds, the influence of free convection is negligible. The results converted to thermal conductivity show very good agreement with the experimental data in the literature.