Measurement of the thermal transport properties of liquids using the front-face flash method

The flash method in the front-face configuration is used to retrieve simultaneously the thermal diffusivity and thermal effusivity of liquids. The thermal conductivity is determined from these measured properties. The method consists in heating with a flash lamp, the front face of an opaque cell containing the liquid sample, and monitoring the cooling process of the same face using an infrared camera. It is shown that a simple one dimensional approach, based on the Fourier's heat diffusion equation for a three layer system, can be used to determine the thermal properties of the liquid. Measurements performed on several non-metallic liquids covering a wide range of thermal properties validate the method. Good agreement is found between the retrieved values of the thermal properties and previously reported values in literature. Moreover, measurements under the front-face configuration are less time consuming than using the classical (rear-face) flash method. Due to its non-contact nature, this method may find practical application for the thermal characterization of complex fluids even when applying external electric or magnetic fields.