润滑油对涡旋鼓风机平衡铁动力学特性的影响及其优化

Influence of lubricating oil on dynamic characteristics of the counterweight in scroll blower and its optimization

针对扇形端面直角结构平衡铁会受到较大阻力矩的问题,提出了机翼型平衡铁优化模型。通过FLUENT软件建立了平衡铁在背压腔内运动的滑移网格模型,模拟了两种平衡铁在背压腔中的非稳态转动过程,得到了平衡铁压力场,周围速度场及边界层分离情况,且计算了其受到的阻力矩。对比分析表明,平衡铁受到的压差阻力矩远远大于摩擦阻力矩,压差阻力矩占总阻力矩的比例可高达83.9%,且在变转速工况下,压差阻力矩随转速增加急剧增加,摩擦阻力矩则缓慢增加;机翼型平衡铁使径向辅助面上的流线轨迹更加均匀有序,边界层分离损失减少,可使其受到的总阻力矩最高降低32.9%,且转速越高,总阻力矩降低越明显。

In view of the problem that the counterweight of fan-shaped rectangular structure will be subjected to a large resistance moment,an optimization model of airfoil counterweight was proposed.The slippage mesh model of the counterweight moving in the back pressure chamber was established by Fluent software,and the unsteady rotation process of two kinds of counterweight moving in the back pressure chamber was simulated. The pressure field,velocity field and boundary layer separation of the counterweight were obtained,and the resistance moment was calculated. The comparative analysis shows that the pressure differential resistance moment is much larger than the friction resistance moment,and the ratio of the pressure differential resistance moment to the total resistance moment can reach up to 83.9%.Under the condition of variable speed,the pressure differential resistance moment increases sharply with the increase of rotational speed,while the friction resistance moment increases slowly.The airfoil counterweight can make the streamline track on the radial auxiliary surface more uniform and orderly,and reduce the loss of boundary layer separation,which can reduce the total resistance moment by up to 32.9%,and the higher the rotational speed,the more obvious the reduction of total resistance moment.