Measurement of the Thermophysical Properties of Anisotropic Insulation Materials with Consideration of the Effect of Thermal Contact Resistance

Abstract

A novel method involving the effect of thermal contact resistance (TCR) was proposed using a plane heat source smaller than the measured samples for improving measurement accuracy of the simultaneous determination of in-plane and cross-plane thermal conductivities and the volumetric heat capacity of anisotropic materials. The heat transfer during the measurement process was mathematically modeled in a 3D Cartesian coordinate system. The temperature distribution inside the sample was analytically derived by applying Laplace transform and the variables separation method. A multiparameter estimation algorithm was developed on the basis of the sensitivity analysis of the parameters to simultaneously estimate the measured parameters. The correctness of the algorithm was verified by performing simulation experiments. The thermophysical parameters of insulating materials were experimentally measured using the proposed method at different temperatures and pressures. Fiber glass and ceramic insulation materials were tested at room temperature. The measured results showed that the relative error was 1.6% less than the standard value and proved the accuracy of the proposed method. The TCRs measured at different pressures were compared with those obtained using the steady-state method, and the maximum deviation was 8.5%. The thermal conductivity obtained with the contact thermal resistance was smaller than that without the thermal resistance. The measurement results for the anisotropic silica aerogels at different temperatures and pressures revealed that the thermal conductivity and thermal contact conductance increased as temperature and pressure increased.

Improvement of Phase Change Materials (PCM) Used for Solar Process Heat Applications

“…The anisotropy of the composite is taken into consideration by inserting the measuring probes in two sections in the direction of the heat transfers, as shown in Figure 9 . This method requires using the calorific value (Cp) to later calculate the thermal conductivity [ 28 ].…”

“…The anisotropy of the composite is taken into consideration by inserting the measuring probes in two sections in the direction of the heat transfers, as shown in Figure 9. This method requires using the calorific value (Cp) to later calculate the thermal conductivity [28]. As it can be seen in Figure 9, for each section of the samples, the Cp is measured in probes of 12.5 mm of diameter and 3 mm thickness.…”

Thermal Insulation and Compressive Performances of 3D Printing Flexible Load-Bearing and Thermal Insulation Integrated Lattice

“…With the development of the aerospace industry, aircrafts face more and more extreme external environments. New challenges to the thermal insulation and load-bearing performance of the aircraft were posed by the complex temperature and mechanical load variations [ 1 , 2 , 3 ]. Common load-bearing and thermal insulation integrated structures include metal foams, sandwich structures, metal lattices, etc.…”

Evolution of contact performance of industry electrical connector based on reliability accelerated testing

“…Guarino et al 14 researched the influence of thermal contact resistance of aluminum foams in forced convection. Han et al 15 studied the properties of anisotropic insulation materials and revealed that the thermal conductivity and thermal contact conductance increased as temperature and pressure increased. Capelli et al 16 analyzed the dependence of contact resistance on temperature through experiments, finding that the contact resistance increased with the increase of temperature, and there was almost a linear relationship between contact resistance and temperature.…”