某SUV行李架的降阻降噪协同优化

Collaborative Optimization of Drag and Noise Reduction for a SUV Luggage Rack

以安装行李架后的某款SUV汽车模型为研究对象,基于协同优化算法,寻找最优的低阻低噪方案。先将降阻和降噪作为单独的2个子学科进行研究,分别寻找出影响气动阻力和气动噪声的关键因素,利用网格变形技术对行李架造型的关键部位进行参数化建立模型。然后通过CFD数值仿真模拟软件对选取的样本点进行计算,同时建立可靠的Kriging响应面模型。最后基于2个子学科的近似模型,构建协同优化模型寻找最优的低阻低噪方案并进行仿真验证分析。研究结果表明:相较于原始汽车模型,单目标优化后的整车模型阻力与噪声分别降低了1.97%和17.99%;协同优化后的整车模型阻力与噪声分别降低了1.60%和14.92%,优化结果与仿真结果的误差分别为0.17%和3.67%,均在工程实际应用可接受误差范围内。

During the driving of the car,the luggage rack not only generates aerodynamic resistance to increase the fuel consumption of the vehicle,but also generates aerodynamic noise,especially when the sunroof is opened,which has a great impact on the driver and passengers,therefore,a reasonable research and analysis on the shape of the luggage rack can reduce drag to save fuel and improve economy,and it can also reduce aerodynamic noise and improve human comfort.This paper takes a certain SUV car model with the luggage rack as the research object,based on the collaborative optimization algorithm(COA),to find the optimal low-impedance and low-noise solution.First,the drag reduction and noise reduction are studied as two separate sub-disciplines,and the key factors that affect aerodynamic drag and aerodynamic noise are found respectively,and the key parts of the luggage rack modeling are parameterized to establish a model by using grid deformation technology.Then use CFD numerical simulation software to calculate the selected sample points,and establish a reliable Kriging response surface model.Finally,based on the approximate models of the two sub-disciplines,a collaborative optimization model is constructed to find the optimal low-resistance and low-noise solution,and the analysis is verified by simulation.The research results show that:The front and rear chamfer of the luggage rack have a greater impact on the aerodynamic assistance and noise of the car.Therefore,without changing the maximum thickness(d max)of the luggage rack,four optimization design variables are designed,namely the front and rear chamfer R 1 and R 2 of the front rod and The front and rear chamfer R 3 and R 3 of the rear rod.Compared with the original car model,the drag and noise of the whole car model after single-objective optimization are reduced by 1.97%and 17.99%respectively;Simultaneously,by calculating the collaborative optimization models under four different weight ratios,a group of 4∶6 resistance to noise ratio is finally established as the final optimization result,as a result,the drag and noise of the vehicle model after collaborative optimization are reduced by 1.60%and 14.92%,respectively,and the errors between the optimization results and the simulation results are 0.17%and 3.67%,respectively,which are within the acceptable error range for practical engineering applications.