发动机用平板型空滤器流动阻力特性分析和改进

为减小平板型空滤器流动阻力以增大进气量，对平板型空滤器流动阻力特性开展了实验研究，获得了空滤器流动阻力随流量变化的规律和阻力构成成分。阻力随流量的增大而加速增大，滤芯阻力约占整个空滤器阻力的一半，入口流量为120 m 3/h时，总阻力为915.3 Pa，滤芯阻力为426.4 Pa。在实验获得滤芯阻力参数的基础上，提出采用多孔介质跃升模型对平板型空滤器内部流场开展三维数值仿真分析，结果表明，仿真结果与实验结果比较吻合，最大误差为5.67%。滤芯阻力同样约占整个阻力的一半，另一半阻力主要为出口处阻力，其余壁面阻力约占15%。最后，在实验和仿真分析的基础上，提出了改进模型并进行了仿真分析。结果表明，改进模型阻力有较大程度的下降，入口流量为120 m 3/h时，总阻力为588.2 Pa，较原始模型下降了32.2%；增大空滤器流通横截面积是减小阻力以增大进气量的有效手段，改进空滤器壁面的平滑性是补充措施。

Analysis and improvement on flow resistance characteristics ofplanar air filter for engines

The flow resistance of planar air filter is measured. The results reveal that the flow resistance accelerando increases with the increase of air velocity and the filter core resistance accounts for about half of the total air filter resistance. When the air inlet flux is 120 m 3/h, the total resistance is 915.3 Pa and the filter core resistance is 426.4 Pa. A 3D numerical simulation using the porous media jump model is established, based on the filter core flow resistance parameter obtained by experiment. The results show that the simulation results are in good agree with the experimental results and the maximum deviation is 5.67%. The filter core flow resistance also accounts for about half of the resistance, and the outlet resistance is the main part of the other half resistance, the rest 15% is the wall resistance. And, an improved model is put forward and the simulation results show that the resistance of the improved model apparently decreases. When the air inlet flux is 120 m 3/h and the total resistance is 588.2 Pa, the resistance of the improved model decreases by 32.2%. The method of increasing the air filter flow cross sectional area is an effective way to reduce the resistance and increase air inlet flux.