受内部空间约束的车身气动优化

把分步遗传算法和以车辆人机工程学为基础设计的车身内部空间约束算子相结合,对车身进行受内部空间约束的气动优化,得到满足不同结构和尺寸的空间约束的三维无轮优化车身.优化车身的气动阻力系数CD值在0.070~0.090之间,气动性能较优.其中一款CD值为0.073的凸头车型优化车身和一款CD值为0.086的凹头车型优化车身可以满足由长前舱、大乘员舱和高后舱构成的内部空间约束条件的要求.内部空间约束的尺寸越小,结构越简单,优化结果越佳.造型越复杂的车身受到空间约束的影响越显著.

Aerodynamic Optimization for Car Body Under Constraints of Inner Space

The process costing genetic algorithm combining with the constraint operator of inner space based on vehicle ergonomics is used to optimize the aerodynamic performance of car body. Three dimensional optimizational car bodies without wheels satisfying constraints of inner space with different structures and sizes are obtained. The coefficients of aerodynamic drag (CD) of those optimized car bodies are within the confines of 0.070 to 0.090, and their aerodynamic performances are all good. Under the constraints of inner space which comprises long fore capsule, big crew capsule and high rear capsule, a cheese head optimized car body whose CD is 0.0728 and a socket head optimized car body whose CD is 0.0860 are obtained. When the size of inner space constraint is smaller and the structure is simpler, the aerodynamic optimization result is better. When the style of the car body is more complex, the constraint of inner space makes a greater difference to the aerodynamic optimization results.