航空弧齿锥齿轮副风阻功率损失分析与优化

Analysis and optimization of windage power loss for aeronautical spiral bevel gear pair

基于CFD理论,利用Fluent求解软件,借助超级计算机强大的并行运算能力对航空弧齿锥齿轮副风阻功率损失进行仿真计算。采用局部综合法建立弧齿锥齿轮副三维模型,选用RNG k-ε湍流模型,考虑平均流动中的旋流流动情况,与标准k-ε模型相比,RNG通过修正湍流黏度并很好地处理了高应变率以及流线弯曲程度较大的流动。齿轮边界运动通过UDF(user-defined functions)函数驱动,同时采用动网格模拟流场形状由于边界运动而随时间改变问题。最后得出无挡风罩和不同挡风罩配置下的齿轮副风阻功率损失,证实了合理安装挡风罩能够有效降低齿轮风阻损失,并分析多组仿真实验间的减速器内流场压力、速度、湍流动能云图变化,得出了最优化的挡风罩配置,以求最小化风阻功率损失,文中减阻效果最好的挡风罩能降低55.3%的齿轮风阻损失,此时挡风罩间隙为1 mm,为工程实际应用挡风罩的设计提供了参考。

Based on CFD theory,the windage power loss of aviation spiral bevel gear pair was simulated by using Fluent solution software with the powerful parallel computing ability of supercomputer.The three-dimensional model of spiral bevel gear pair was established by local synthesis method.The turbulence model of RNG k-ε was selected to consider the swirl flow in the average flow.Compared with the standard k-ε model,the turbulence viscosity of RNG was corrected and the flow with high strain rate and large curvature of the flow line was well treated.The gear boundary motion was driven by UDF(user-defined functions) functions,and the change of flow field shape over time due to boundary motion was simulated by dynamic grid.Finally,the windage power loss of the gear pair with different shroud configurations was obtained.It is confirmed that the reasonable installation of the shroud can effectively reduce the gear windage loss,and the variations of cloud images of the flow field pressure,velocity and turbulent kinetic energy in the gearbox between several groups of simulation tests were analyzed,and the optimal shroud configuration was obtained to minimize the windage power loss.The shroud with the best drag reduction effect can reduce the gear windage loss by 55.3%,and the shroud clearance is 1 mm in this case,providing a reference for the design of shroud in engineering practice.