Simultaneous measurement of thermal properties and convective heat transfer coefficient of individual carbon fiber using Raman spectroscopy

The new developed laser-Raman method was used to measure the thermal conductivity of individual carbon fiber at 333.15 K. The local temperature along the individual fiber was determined by Raman shift. The measuring result without concerning thermal contact resistance is 110.6 W·m^-1·K^-1, which fits well with data from direct-current method. Then the method is made better. By changing laser heating spot, the thermal contact resistance is determined. And then the intrinsic thermal conductivity is determined to be 135.0 W·m^-1·K^-1 by concerning the thermal contact resistance. Moreover, by changing laser heating power the laser absorptivity is determined. And when the fiber is being heated in the air, the convective heat transfer coefficient is obtained by iterative solution.