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Mechanical Engineering

Mechanical and Aerospace Engineering Faculty Publications

Series

2012

Thermal conductivity

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Spatially Localized Measurement Of Thermal Conductivity Using A Hybrid Photothermal Technique, Zilong Hua, Heng Ban, Marat Khafizov, Robert Schley, Rory Kennedy, David H. Hurley Jan 2012

Spatially Localized Measurement Of Thermal Conductivity Using A Hybrid Photothermal Technique, Zilong Hua, Heng Ban, Marat Khafizov, Robert Schley, Rory Kennedy, David H. Hurley

Mechanical and Aerospace Engineering Faculty Publications

A photothermal technique capable of measuring thermal conductivity with micrometer lateral resolution is presented. This technique involves measuring separately the thermal diffusivity, D, and thermal effusivity, e, to extract the thermal conductivity, k = (e2/D)1/2. To generalize this approach, sensitivity analysis is conducted for materials having a range of thermal conductivities. Application to nuclear fuel is consider by performing experimental validation using two materials (CaF2 and SiO2) having thermal properties representative of fresh and high burnup nuclear fuel. The measured conductivities compare favorably with literature values.


Parametric Study Of The Frequency-Domain Thermoreflectance Technique, C. Xing, C. Jensen, Z. Hua, Heng Ban, D. H. Hurley, M. Khafizov, J. R. Kennedy Jan 2012

Parametric Study Of The Frequency-Domain Thermoreflectance Technique, C. Xing, C. Jensen, Z. Hua, Heng Ban, D. H. Hurley, M. Khafizov, J. R. Kennedy

Mechanical and Aerospace Engineering Faculty Publications

Without requiring regression for parameter determination, one-dimensional (1D) analytical models are used by many research groups to extract the thermal properties in frequency-domain thermoreflectance measurements. Experimentally, this approach involves heating the sample with a pump laser and probing the temperature response with spatially coincident probe laser. Micron order lateral resolution can be obtained by tightly focusing the pump and probe lasers. However, small laser beam spot sizes necessarily bring into question the assumptions associated with 1D analytical models. In this study, we analyzed the applicability of 1D analytical models by comparing to 2D analytical and fully numerical models. Specifically, we …