The LED technology is developing rapidly, resulting in even higher efficiencies and hence a greater increase in the generated light output. As the light emitting surface (die) area is of the order of some square millimetres, high radiant flux densities in the visible part of the spectrum can be observed. Abnormally high temperatures of the phosphor or of the optics can arise from an accidental absorption of the light, caused due to the presence of insects or foreign particles in the immediate vicinity of the LED. This can lead to a failure of the LED module.
STAR-CCM+ and its multi-band radiation model is used in order to investigate the impact of this phenomenon on the thermal behaviour of luminaires.