Simultaneously estimating the thermal conductivity and thermal diffusivity of a poorly conducting solid material using single surface measurements

Fernando Costa Malheiros; Jefferson Gomes do Nascimento; Ana Paula Fernandes; Gilmar Guimarães

doi:10.1063/1.5122756

Simultaneously estimating the thermal conductivity and thermal diffusivity of a poorly conducting solid material using single surface measurements

Rev Sci Instrum. 2020 Jan 1;91(1):014902. doi: 10.1063/1.5122756.

Authors

Fernando Costa Malheiros¹, Jefferson Gomes do Nascimento², Ana Paula Fernandes², Gilmar Guimarães²

Affiliations

¹ Minas Gerais State University, Street 20, 1600, Campus Pontal, Ituiutba, MG, Brazil.
² Federal University of Uberlândia, School of Mechanical Enginneering, Av. João Naves de Ávila, 2121, Campus Santa Mônica, Uberlândia, MG, Brazil.

PMID: 32012527
DOI: 10.1063/1.5122756

Abstract

This paper presents a new experimental method that simultaneously obtains the thermal conductivity and thermal diffusivity of a solid. This technique uses a new surface probe with a resistance heater, two thermocouples, and a heat flux sensor. In this method, part of the top of the sample is heated, and two regions on this surface (one heated and the other not) are used to estimate the thermal properties of the material. This technique minimizes two distinct functions that are defined from surface temperature measurements, using, however, different thermal concepts. The first uses the gain ratio between two surface temperatures to determine the thermal diffusivity. The second uses the well-known square quadratic error function calculated with the same experimental and theoretical values of the temperatures of the surface to estimate the thermal conductivity.