Numerical modeling and experimental validation of focused surface heating using near-infrared rays with an elliptical reflector

Focused surface heating (or focused heating) using near-infrared (NIR) rays with an elliptical reflector has been widely used in industrial fields. Under ideal conditions, an elliptical reflector can gather NIR heat flux from an NIR heat source by reflection to a focus point. Under engineered conditions, however, NIR heat flux is distributed out of the focus point, being not negligible. Therefore, a thermal model that considers the distribution of heat flux is required to simulate focused NIR heating using an elliptical reflector. However, there has been little study on thermal models that consider the heat flux distribution for the analysis of focused NIR heating using an elliptical reflector. A numerical model is proposed for the simulation of focused heating and the physical meaning of the proposed model is discussed in this paper. Finite element analyses of transient heat transfer using the proposed model were conducted and compared with experimental results of heating dual phase (DP) 980 steel in several conditions. The result comparisons have validated the practical applicability of the proposed numerical model.