汽车主动进气格栅开启角度的匹配优化

Optimization of the Opening Angle of the Vehicle’s Active Grille Shutter

鉴于汽车主动进气格栅的开启角度直接影响着整车风阻和散热性能,本研究以降低油耗为目标,并以实车为例,进行了基于车速和发动机冷却需求的进气格栅开度优化。首先构建某MPV车型的CFD风洞模型,仿真得到不同车速和格栅角度下散热器的进风量。通过发动机热平衡实验得到发动机在不同转速和负荷率下的散热量,进而计算得到不同工况下冷却系统的需求散热量和需求进风量,并以满足冷却系统的散热需求和降低整车风阻为原则进行格栅开度的匹配优化。最后基于实车验证得到整车在怠速下瞬时油耗下降0.076L/h,30km/h、70km/h和120km/h等速下油耗分别下降0.08L/100km、0.11L/100km和0.15L/100km。

In view of the fact that the opening angle of the Active Grille Shutter directly affects vehicle wind resistance and heat dissipation.The study aims to reduce fuel consumption and takes the actual vehicle as an example to carry out the optimization of the intake grille opening based on the vehicle speed and engine cooling demand.Firstly,constructing the CFD wind tunnel model of a MPV model which obtaining the air intake of the radiator under different vehicle speeds and grille angles.Through the engine heat balance experiment to obtain the heat dissipation of the engine at different speeds and load rates and calculate the required heat dissipation and the required air intake of the cooling system under different working conditions.And then optimize the grille opening degree based on the principle of meeting the cooling demand of cooling system and reducing vehicle wind resistance.Finally,based on the actual vehicle verification,the instantaneous fuel consumption of the whole vehicle decreased by0.076 L/h at idle speed,and the fuel consumption decreased by 0.08 L/100 km、0.11 L/100 km and 0.15 L/100 km respectively at the same speed of 30 km/h、70 km/h and 120 km/h.