Numerical Simulation And Experimental Research On Thermal Conductivity Measurement By 3-Omega Method

Thermal conductivity is one of the important thermophysical parameters of materials.Its research and development play a huge role in solving the problems of energy crisis,environmental pollution and sustainable economic development.In recent years,the 3-Omega method has been widely used to measure the thermal conductivity of bulk and thinfilm materials.The technical problem still faced is that the metal detector is attached to the surface of the sample in the traditional 3-Omega method cannot be transplanted.Not only destroys the independent integrity of the surface of the sample,but also the sample and the detector can not be reused,so the experiment cost is relatively high.This article aims to build a thermal conductivity experimental platform based on the3-Omega method,which can stably and accurately measure the thermal conductivity of solid materials.Based on the two-dimensional heat conduction model under the anisotropic multilayer structure derived by T.Borca et al.,the average temperature rise formula of the metal heater in the double-layer system is obtained,which provides a theoretical basis for the research and development of the 3-Omega sensor.The feasibility of 3-Omega sensor development was studied by numerical simulation method,and the corresponding model deviations of metal heaters in different width and thickness combinations were calculated by simulation.And the appropriate 3-Omega sensor size range was obtained,and then the influence of different heating power,frequency range on the thermal conductivity measurement results.To obtain the best experimental conditions,and guide the smooth construction of the experimental platform;refer to the numerical simulation results,and carry out the metal detectors in the traditional 3-Omega method.With appropriate improvements,a sandwich-type 3-Omega sensor was fabricated using photolithography and corrosion processes.The length,width,and thickness of the metal heating wire are different from those of the traditional metal heater,and the metal pad is symmetrical about the nickel wire axis.The supporting data acquisition system and data acquisition software were designed and developed,and a thermal conductivity experimental platform based on3-Omega sensor have been successfully built.Subsequently,the thermal conductivity of the three materials stainless steel,quartz glass and PMMA was experimentally studied to verify the stability and reliability of the experimental platform.