Thermal design and simulation of automotive headlamps using white LEDs

With an urgent need for energy conservation and pollution reduction, the trend of replacing traditional incandescent or fluorescent lamps with high-power LEDs is growing more and more popular. In this research, high power white LED chips are used in automotive headlamp low beam system design. Several different cooling devices are designed for headlamp cooling, the heat dissipation performances are simulated and analysed both by the finite volume method (FVM) in FloEFD and experimental measurements. The simulation and experimental results show that nature convection cooling is not an effective method for LED headlamp cooling. Heat sink combined with heat pipes technology can greatly improve the heat dissipation performance. When the liquid filled ratio is 10%, heat pipes with evaporator length 30 mm, adiabatic section length 40 mm and condenser length 50 mm have the best cooling performance. Cooling device with heat pipes placed dispersedly makes the junction temperature lower than cooling device with heat pipes isometric placed in the same plane. The liquid filled ratio of heat pipes can influence the equivalent heat transfer coefficient significantly, and the optimal filling rate is 30% in our study.     

基于品牌设计的汽车前照灯造型设计分析

目的基于品牌设计理念的汽车前照灯造型设计的创新方法和设计策略研究。方法在分析前照灯设计重要性的基础上,运用品牌设计理念,以知名汽车品牌产品为分析对象,提出以前照灯塑造品牌家族形象的具体造型方法,并以实际案例说明在车灯设计开发中,品牌共性与产品个性在前照灯设计中的应用以及品牌形象与流行形象在前照灯设计的应用中需要注意的具体问题。结论在前照灯设计开发中,要以\"塑造品牌形象\"为重心,在设计应用中需要综合权衡\"品牌共性与产品个性\"以及\"品牌形象传承和时代形象塑造\",根据品牌自身的发展脉络,制定造型设计策略。     

基于Zemax的新型匀光鳞甲反光杯系统设计

为进一步优化传统反光杯在匀光、防眩光等方面的问题,基于Zemax仿真软件设计出了一种匀光性能优越的鳞甲反光杯。仿真结果表明,在杯前25 m处的配光屏幕上,最大光照强度为234 lx,中心HV点的光照强度大于0.80 E_max,各指标均符合国标GB 25991—2010《汽车用LED前照灯》的要求。将鳞甲反光杯与微透镜阵列相结合,使配光屏幕上的最大光照强度减小至59.51 lx,在各项指标仍符合国家标准的情况下,该系统的光斑能量更加均匀,且中心区域的光强进一步降低,光斑边缘过渡更加柔和,防止汽车远光灯产生眩光的效果更好,可以大量应用于汽车前照远光灯。