基于硬点-骨架约束的汽车低阻曲面优化研究

Study of Automobile Low Resistance Surface Optimization Based on Hard Points-Skeleton Constraint

针对汽车车身局部修形传统气动减阻方法存在经验式和盲目性问题,以某款成熟简化实车发动机罩低阻曲面优化减阻为例,提出了基于硬点-骨架约束的车身低阻曲面优化设计法.采用DOE(design of experiment)试验设计方法对发动机舱罩进行硬点采样,通过硬点-骨架约束建立样本曲面.构建以硬点为设计因子,阻力系数为响应值的数学近似模型,并使用多岛遗传算法获得发动机舱罩理论最优解.计算表明:优化后的实车车模气动阻力减少3.32%,证明了硬点-骨架约束在车身减阻上的可行性和有效性.

Aiming at car body using traditional methods of local modification aerodynamic drag reduc- tion with experience, blindness and other problems, taking a ripe simplified real vehicle engine hood low resistance surface optimization of drag reduction for example, the low resistance surface optimiza- tion design method is put forward that based on hard-skeleton constraints. Using design of experiment （for shot DOE） methods to sample the hard points of vehicle engine hood , then the sample surface is established through a hard points-skeleton. A mathematical approximation model of hard point is con- structed as design factors and drag coefficients for response values. Taking advantage of multi-island genetie algorithm to get engine hatch theory of optimalsolutions . the calculation shows that the opti- mized real vehicle model aerodynamic drag is reduced by 3. 32%, which proves that the feasibility and effectiveness of hard-skeleton constraints in automobile body drag reduction.