Numerical analysis of solid thermal diffusivity based on laser photothermal method

Solid thermal diffusivity is very important to study unsteady heat conduction under low temperature.In order to study solid thermal diffusivity under low temperature,sample thermal diffusivity under different temperature is computed in term of thermal diffusivity theory model in the paper.Besides,function relation between laser frequency and phase lag is gained by numerical simulation.The two groups of data are approximately equal by contrasting the numerical result and experimental result.The research indicates that solid thermal diffusivity could be measured availably by laser photothermal.Numerical simulation of solid thermal diffusivity under low temperature shows that solid thermal diffusivity changes remarkably when the scope of temperature is from 20 K to 80 K,however,the change is less from 80 K to 300 K.