摩托车散热器护罩结构对其进风量的影响分析

Analysis of the impact of motorcycle radiator shield structure on its inlet air volume

为保护散热器不被泥土污染,需在散热器进风端添加散热器护罩。散热器护罩添加后对散热器进风量有明显的影响。为获取较优的散热器护罩结构设计,采用CFD分析方法搭建摩托车整车外流场计算域模型,结合不同散热器护罩结构方案,分析散热器护罩结构对其进风量的影响,选取合适的散热器护罩方案开展整车实验验证。结果表明:散热器护罩上导流板角度130°且散热器护罩与芯体间的间隙为1 mm时,散热器进风量为281.7 g/s,与无护罩状态的进风量相当。护罩与芯体间存在间隙可提升散热器进风量,建议间隙控制在1~2.5 mm;散热器护罩网孔倾斜和导流板开孔不利于风量提升。经对比测试,怠速工况、最高车速工况及最大扭矩工况下,散热器添加护罩后的发动机出水温度与无护罩状态的发动机出水温度基本一致。适当减小风扇罩挡风面积可进一步提升散热器进风量,散热器添加护罩后,人体大腿两侧不会出现明显热风。研究结果可为摩托车散热器护罩结构设计及优化提供理论参考。

To protect the radiator from soil contamination,a radiator shield is needed at the inlet of the radiator.However,the addition of radiator shield exerts a huge impact on the inlet air volume of the radiator.To obtain an optimal design of the radiator shield structure,the CFD analysis method is employed to build a computational domain model for the external flow field of the motorcycle.The impacts of different radiator shield structures on their inlet air volume are analyzed and a suitable radiator shield scheme is selected for vehicle experimental verification.Our results show with an angle of 130°on the guide plate of the radiator shield and a gap of 1 mm between the radiator shield and the core,the inlet air volume of the radiator is 281.7 g/s,which is equivalent to the inlet air volume without a shield.As the gap between the shield and the core body increases the inlet air volume of the radiator,it should be controlled at 1~2.5 mm.The inclination of the hole on radiator shield and the opening of the guide plate are not conducive to increasing the air volume.Our comparative tests show the engine water outlet temperature stays basically the same before and after adding a radiator shield under idle conditions,maximum speed conditions,and maximum torque conditions.Properly reducing the windproof area of the fan cover further increases the inlet air volume of the radiator.After adding a shield to the radiator,no hot air is found between the motorcyclist’s thighs.Our research may provide some valuable references for the design and optimization of the radiator cover structures of motorcycles.