Abstract
In order to predict water condensation in automotive headlamp at an early stage of development process, CFD analysis of the flow in the headlamp is attempted. At first, the CFD analysis on the headlamp unit removed from vehicle was conducted. The result was similar to the experimental result, thus the validity of this analysis was confirmed. Furthermore, water condensation in the headlamp on the vehicle was studied based on the CFD analysis and experiment. The results shows that the boundary condition of the headlamp, considering thermal radiation from engine, airflow induced by the vehicle running speed, and humidity distribution around headlamp, is required to predict water condensation problem.