Analysis on transient test of thermal conductivity of anisotropic materials based on laser heating
Considering the transient process of laser heating sample,the heat transfer model of anisotropic material was established.The influences of heating time,spot diameter and other parameters on the temperature rise of typical materials under different laser power and sample thickness were discussed.The reasonable range of laser parameters and sample size was determined by analysis.Furthermore,the sensitivity and influencing factors of the transient test method were analyzed by combining the identification model of thermal conductivity inversion based on temperature rise.The results showed that the inversion errors of thermal conductivity,heating power and surface emissivity were less than 2％without considering the temperature test error in the experiment.In the actual test process,the initial temperature field uniformity and emissivity had a greater impact.When the test temperature was 800 K and the error was 1％,the inversion accuracy of thermal conductivity was high(less than 2％)and the deviation of surface emissivity was large.When the emissivity of material was obtained and the non-uniformity of initial temperature field was 0.13％,the deviations of axial and radial thermal conductivity can be reduced obviously by simultaneous inversion of thermal conductivity and correction coefficient of initial temperature field.
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