扰流柱对车用液力缓速器空损抑制效应分析

Suppression effect analysis of spoiler on idling loss of vehicular hydraulic retarder

为抑制车用液力缓速器空转功率损失,对扰流柱机构抑制空损效应进行三维流场数值模拟.针对扰流柱布置形式,建立定轮安装扰流柱与未安装扰流柱两种情况的周期计算模型,以降低仿真成本,并在空转工况与充液工况下,分别对两模型计算精度进行验证.计算不同转速下安装扰流柱与未安装扰流柱周期模型的空损,获取空转工况下空气对两模型叶片所施加的制动功率,得到周期流道速度场、压力场分布状态,并对比分析了扰流柱对空气流场扰动效果以及空损抑制作用.结果表明,扰流柱机构能有效阻碍空气的循环流动,某缓速器在动轮转速3 400 r/min时空损可降低48.4%,有效提升了车辆的功率利用率.

To suppress the idling loss of vehicular hydraulic retarder,the suppression effect of spoiler on the idling loss was investigated by 3-D flow field numerical simulation. Based on the arrangement of spoilers,the periodic calculation models with and without spoiler installed in the stator were established to reduce the cost of simulation,and the accuracy of numerical models was verified in idling condition and oil-filling condition respectively. At different rotating speed,the calculation of idling loss was further conducted for two periodic models. The braking power applied by air was calculated in idle condition,and the distribution of velocity field and pressure field were also obtained. Then the effect of spoiler disturbing air flow and reducing idling loss was comparatively analyzed. The result shows that the spoiler can impede the air circulation flow effectively,the idling loss of the hydraulic retarder can be reduced to 48. 4% at the rotary speed of 3 400 r / min,and the vehicle power utilization can be enhanced efficiently.