【作者】 贾彦龙；

【导师】 王仁人；

【作者基本信息】 山东轻工业学院 ， 机械电子工程， 2008， 硕士

【摘要】 空气滤清器是内燃机进气系统的重要部件,直接影响内燃机性能。提高空气滤清器内气流速度分布均匀性,降低压力损失,是提高其滤清效率、延长其使用寿命的重要措施,也是空气滤清器结构设计的关键。应用先进的三维数值计算技术可以获得空气滤清器内部流场详细信息,得到其综合评价结果,为空气滤清器结构优化设计提供重要的理论依据。应用多孔介质模型模拟了空气滤清器粗滤器内的丝网和精滤器内的滤芯,建立了空气滤清器内部流动数学模型。利用Pro/Engineer建立了空气滤清器三维几何模型,利用STAR-CD前处理器Pro/am生成了其流场三维非结构化计算网格。在确定初值、边界条件后,应用STAR-CD求解器STAR较详细地计算了空气滤清器内部流场,利用压力云图和速度矢量分布图等进行了内部流场显示,得到了速度场、压力场的分布规律。结果表明:气流对空气滤清器入口部分拐角处产生了强烈冲击,出口处的速度分布不均匀;空气滤清器内部存在明显涡流,造成较大的压力损失。分析计算了空气滤清器入口处壁面圆弧大小对其压力分布、速度分布的影响。在此基础上,对空气滤清器入口处进行了结构优化设计,以圆弧结构取代原直线结构。结构优化前后的计算分析结果表明:优化后入口部分内部流场速度分布均匀性提高了10%,进出口压力损失降低了32%。更多还原

【Abstract】 As an important component of the internal combustion engine intake system, the air filter has directly effect on its performances. The improvement of the flow velocity distribution and the reduction of the pressure loss are helpful to increase air filter filtration efficiency and prolong its service time, and they are also the keys to design air filter. With advanced three-dimensional numerical simulation technology,the detail flow filed in the air filter can be obtained, and the overall evaluation can be gotten, and the important theoretical foundation can be provided for the structure optimization of the air filter.The mesh in the preliminary filter and the fibre core of the fine filter are simulated with a porous medium model, and then the mathematical model of the flow in air filter is set up. The three-dimensional geometry models of the air filter are made by Pro/Engineer, and the numerical simulation computation grids of the flow field in air filter are generated by STAR-CD pretreatment tool Pro/am.Based on STAR-CD, the simulation of the flow field in the air filter is carried out more detailed after the initial and boundary values are determined. The flow field visualization is done with the pressure atlas and velocity vector, the pressure and velocity distributions are gotten. The results show that the flow had a strong impact on the entrance corner of air filter inlet part, the velocity distribution of the exit is uneven, and the vortexes exist in air filter, so that it caused greater pressure loss.The influences of inlet box arc in inlet of the air filter on the pressure and velocity distributions are simulated and analyzed, and then the inlet box shape of the air filter is optimized using the arc structure to replace the original linear structure. The optimization results show that the velocity distribution uniformity is enhanced 10% and the pressure loss is reduced 32% after the structure optimized.更多还原