中文摘要：

以捷达1.6 L汽车内燃机为试验母体,将黄缘真龙虱体表的减阻、耐磨凹坑结构应用于内燃机主要摩擦副活塞裙部上,并进行优化设计。首先,根据龙虱体表凹坑排布的形状和结构尺寸确定仿生孔径和间距范围,通过相对速度减阻率选定最优仿生孔径。其次,根据标准活塞裙部热-结构耦合分析应力排布情况,设计变孔径、变行间距排布的仿生孔,并制定正交试验方案。对仿生活塞模型进行有限元热-结构耦合分析,选取3个典型目标变量作为试验指标,进行优化设计得出主次因素和最优组合。最后,选取标准活塞、最优性能仿生活塞、最优组合活塞,进行内燃机耐久性台架试验。通过检测各个气缸活塞运行至上止点时其顶部温度、气体压力变化率、活塞磨损量、磨损后活塞裙部表面粗糙度验证了仿生活塞减阻、耐磨的优越性。

英文摘要：

Research of existing automobiles of energy-saving and emission reduction is very important in the interim period before popularization of new energy automobiles. Some research results showed that about 50% frictional loss of engine was generated from friction pair of piston-cylinder liner system. Based on great usage amount of engines,frictional loss of engine was reduced within a narrow range; it could exert a large influence on energy consumption and environmental enhancement. The 1. 6 L engine of Jetta car was used as testing subject. The pits on the Cybister bengalensis＇ surface,which could reduce drag and increase wearability,were applied to the main friction pair of engine—piston skirt for the first time.Firstly,the ranges of bionic apertures and separation distances were designated according to the configuration sizes of pits of cybister surface. Then the optimal bionic apertures and separation distances were determined by relative speed drag reduction rate on the basis of relative speed of bionic piston under the three calibration conditions. The ultimate speed of bionic piston was increased as drag reduction rate increased,and the anti-drag and wear-resisting were improved with smaller friction of bionic piston.Secondly,the stress arrangement of thermal-structure coupling analysis of standard piston skirt showed that the maximum stress was at the top and the maximum deformation was at the bottom. Variable aperture and variable line spacing of bionic holes was innovatively designed. Larger aperture and greater line spacing were located near the piston top. Three levels and three factors orthogonal test was made.Level one was holes distribution,which included uniform form,stagger form,line by line to increase;level two was bionic hole,including through-hole,pit,pit and through-hole alternating; level three wasbionic aperture,including three bionic aperture sizes. Under the worst conditions,standard and nine bionic pistons were done by finite element thermal-structure coupling analysis. Three typical ta