Thermal analysis of automotive lamps using the ADINA-F coupled specular radiation and natural convection model

A thermomechanical analysis based on a contact temperature measurement

“…This effect is caused by the buoyancy force created by the density and temperature gradient. The detailed lamp internal airflow pattern obtained in previous research [3] shows that the maximum velocity occurs in the region above the bulb, while the region below the bulb shows a lower velocity. A counter-rotating vortex exists near the lens as the lens heating drives the air upwards [3].…”

“…The detailed lamp internal airflow pattern obtained in previous research [3] shows that the maximum velocity occurs in the region above the bulb, while the region below the bulb shows a lower velocity. A counter-rotating vortex exists near the lens as the lens heating drives the air upwards [3]. Other research also shows that natural convection flow is also strong in the longitudinal direction of the headlamp [2].…”

“…This temperature distribution is determined by the mechanisms of natural heat convection, conductance, and radiation. Owing to the spaces between the parts of the headlamp and the different temperatures of these parts, a complex natural convection is established [2][3][4], which then strongly influences the local temperature increase of the fog-lamp housing. Natural convection in enclosures is the result of thermal and momentum interactions between a finite size fluid system and the confining walls.…”

“…The highly specular aluminized surface reflects the majority of the incident radiation from the filament and bulb, which is then absorbed and transmitted by the lens. The bulb re-radiates at its own surface temperature [3]. Radiation, however, affects only those parts that are visible from the bulb and the bulb shield, which means that radiation increases the temperature of the housing in front of the reflector.…”

“…One obvious way to determine the temperature distribution over the fog-lamp housing would be a simulation using a computational fluid dynamics (CFD) analysis. However, such an analysis is very complex because it is necessary to mesh all the internal parts of the fog lamp and the air inside [1,3,6,7]. Such a calculation requires much computational power, with the need to determine many calculation parameters specific to the problem.…”