基于Fluent的无摩擦气缸活塞结构设计仿真

摘要

Aiming at the low radial bearing capacity,high gas consumption and working instability of the current cylinder-piston,combining with the ideas of air bearing,a more innovative frictiouless cylinder-piston was presented.Based on the CFD software Fluent,the frictionless cylinder-piston fluid modal was established and the distribution of pressure along the axial direction of the piston was obtained.And comparing the method of traditional theory calculation and Fluent simulation,the relationship between eccentricity and radial bearing capacity was acquired.It is proved that the result of the traditional theory calculation and Fluent simulation is basically the same.And the latter's calculation result of the beating capacity is less than 3.2％ when eccentricity is in the range of 0.1 to 0.3.The smaller the eccentricity is,the smaller the error of simulation is.The results indicate that the design of cylinder-piston based on Fluent is validity and reliable.%针对现有气缸-活塞结构径向承载力低、耗气量大以及工作失稳等问题,结合空气轴承的设计思路,提出了一种新颖的无摩擦气缸活塞的设计方法.利用流体仿真软件Fluent,建立了无摩擦气缸活塞的流体模型,并得到了气膜沿活塞轴向的压力分布情况;同时,采用传统理论计算与Fluent仿真计算进行了对比研究,得到了活塞偏心率与径向承载力的关系.研究结果表明,传统理论计算与Fluent仿真计算结果基本吻合,后者在偏心率处于(0.1～0.3)范围内时,承载力计算误差低于3.2％;并且偏心率越小,仿真计算误差越小,说明利用Fluent对气缸活塞结构设计具有正确性以及可靠性.