Experimental study on the regulation of radiative heat flux by coating SiC film

Near-field thermal radiation has received increased attention due to the performance of efficient energy conversion. In this study, the vacuum gap distance between two objects, separated by 1 μm polystyrene particles, is investigated. The entire experimental device is installed in a highly vacuumed environment to ensure that the radiative heat flux dominates the main mode of heat transfer. Compared with the measurement of near-field thermal radiation of flat glasses, it is found that coating SiC film on the hot side of optical glass can reduce heat transfer. However, through theoretical analysis, it is shown that there is an optimal thickness of SiC film of around 1 μm. In addition, the experimental data and theoretical analysis results are consistent. The experiment demonstrates that the regulation of radiative heat flux can be achieved by coating. As the thickness of SiC film on the hot side increases, the radiative heat flux decreases.