Condensation in Automotive Lamps and Solving Strategy

Dr. ShengchunSha*, Dr. Henning Kiel, Nan Wang, Wei Jiang, Lijun Jin

SAIC Volkswagen Automotive Co., Ltd.;Shanghai, P.R.China

*Contact email address: shashengchun@csvw.com

Abstract: Condensation in automotivelamps is an effect which must be reduced to the minimum. Although a foggingincident in automotive lamps is as natural as at a mirror on a bathroom after ashower, a client does not accept it in automotive parts. The styling of modernlamps catches much more attention to the parts in detail than in earlier daysand accordingly, far more parts are integrated, that possibly reduce theability to remove condensation. Especially in the Chinese market, the weather conditionsare very demanding: long period high humidity and suddenly low temperaturesoccur as well as dust, against which the lamp must be protected. Moreover, the demandson quality of local clients are high. Therefore, the local requirements on agood lamps design against condensation are challenging.

In the design process of automotivelamps, it’s necessary to make early decisions based on simulations. Therefore,current simulation methods, its abilities and limits on condensation arediscussed in this paper. The physical background of condensation in automotivelamps and its connection to certain weather conditions and traffic situationsare described. Influencing factors on lamps ability for removing condensationin are discussed. Finally, the demands on simulation methods to provide the calculationmodels and necessary accuracy are described.

Keywords- condensation;automotive lighting; lamps; humidity; dew point; CFD; trancient simulation;