Inverse method for estimating local thermal diffusivity of biomaterials

This paper describes an inverse method for estimating the local thermal diffusivity of biomaterials such as meats and vegetables using a thermophysical handy tester. A thermophysical handy tester is a fast, non-invasive, in-situ, local device for measuring the thermophysical properties of a material. However, it cannot be applied to soft or liquid materials precisely. In this study, an inverse analysis of this device was conducted to make it applicable to the measurement of the thermophysical properties of these materials. In the proposed inverse analysis, a real coded genetic algorithm (GA) was used to minimize the objective function. First, a calibration experiment of the device was conducted by using water to determine the apparatus constant. Then, this inverse method was validated by measuring the thermal diffusivity of some materials such as agar-gelled water, silicone oil, and glycerol. It was found that, the estimated thermal diffusivity shows good agreement with the reference value. Moreover, the thermal diffusivity of various biomaterials such as vegetables and meats was estimated, and reasonable values could be obtained by a proposed method.