These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

Although just one component associated with a vehicle that has thousands of parts, headlights play a crucial role in driver and passenger safety. Specifically, both rear and front headlights illuminate a vehicle whether it be day or night, thereby allowing other road vehicles to perceive the vehicle in question. In summertime, the main source of headlight ray obstruction is bugs or insects that accumulate on the headlight surface, particularly when travelling at high speeds. However, during the wintertime, the main cause of light ray obstruction occurs prior to travelling, when the vehicle is still warming-up. In this phase, often ice that has accrued on the headlight'™s cover while the vehicle is at rest needs to be melted away via heat emitted from a wire filament embedded in the Makrolon polycarbonate cover of the headlight. When the driver and/or passengers are in a hurry, it is imperative that the defrost of the headlight ice layers occurs as rapidly as possible. With the increasingly more powerful hardware and software capabilities on the market, it is now possible to optimize the headlight defrost scenario, where the hot wire filament melts away the ice layer on the headlight'™s front, for reduced time entirely virtually. The present work uses modelling and simulation (MODSIM) on Dassault Systèmes'™ unifying computer-aided engineering (CAE) software platform, where both computer-aided design (CAD) and Navier-Stokes based computational fluid dynamics (CFD) tools are combined, to optimize this defrost time. A key aspect of the current workflow is the H2O phase change that is modelled by implementing a temperature dependent specific heat capacity with a spike at 0°C to account for H2O'™s heat of fusion. Furthermore, the MODSIM process allows the simulation scenario set-up of a parameterized CAD model to be automatically updated when the geometry in question is changed. For the headlight geometry in question, which is provided by a Tier I automotive component supplier called Weldex, the headlight filament wiring is parametrized and optimized in shape for minimized defrost time using a parametric design study approach. The constraint is that the headlight geometry itself cannot be changed, as this is dictated by the automotive original equipment manufacturer (OEM) that has purchased the headlight.