摘要
以Ahmed车辆为研究对象,采用CFD数值模拟的方法,研究非光滑棱纹仿生结构对车辆空气动力学特性的影响。对不同行驶速度下原车尾涡速度矢量分布以及升阻力系数的仿真计算,并根据风洞试验结果验证数值模拟的有效性。在原车尾部设计非光滑棱纹仿生结构,以阻力系数和升力系数为优化设计目标函数,以仿生结构的几何尺寸,空间布置尺寸,以及行驶车速作为设计变量,建立Kriging近似模型,并采用多目标遗传算法进行带有棱纹仿生结构的Ahmed车辆模型优化分析。经CFD验证,优化后的带有棱纹仿生结构的Ahmed车辆模型阻力系数降幅约为5%,升力系数降幅约为29.35%,能够起到显著的减阻增稳效果。计算结果也表明,建立的Kriging近似模型的误差为2%左右,可信度较高。
The impact of non-smooth ribbed bionic structure upon the aerodynamics characteristics for a Ahmed vehicle was analyzed by CFD simulation. Simulation calculations on velocity vector distribution of trailing vortex and the drag/lift coefficient were undertaken under variable vehicle speeds,validating its effectiveness through the comparison against the wind tunnel test results. Non-smooth ribbed bionic structure was designed on the inclined surface at the rear of the model,and Kriging surrogate model was established by taking drag coefficient and lift coefficient as optimization objective and taking the geometry size of bionic structure,space layout size,and vehicle speed as design variables. Multi-objective genetic algorithm was used to optimize the Ahmed model with ribbed bionic structure. The CFD simulation results show that the coefficient of drag of the Ahmed model integrated ribbed bionic structure is declined by 5% and the lift coefficient is reduced by 29% after optimization,which has the significant effect on the drag reduction and stability enhancement. The results also show the error of Kriging model established is about 2%,which leads to the better reliability.
出处
《机械设计与制造》
北大核心
2018年第3期244-247,共4页
Machinery Design & Manufacture
基金
教育部高等学校博士学科点专项科研基金资助项目(20113227110014)
江苏省普通高校研究生科研创新计划项目(CXL0X12_0657)
关键词
仿生
计算流体力学
气动特性
优化
Engineering Bionics
CFD
Aerodynamics
Characteristics
Optimization
