轴类间隙内摩擦损失模型验证及流动特性分析

To predicate the windage loss in gap of rotating machinery, the four common windage loss models are verified systematically, and the flow characteristics in gap are analyzed in detail. Firstly, the numerical method is verified by the published experiment data of windage loss and velocity distribution in gap. Secondly, the prediction accuracy of these four models is validated under different linear velocity and fluid density conditions, and the flow characteristics are analyzed in detail. The results show that the windage loss and velocity distribution obtained from the Reynolds stress model deviate only slightly from experimental results, verifying reliability of the numerical method. Within a linear velocity of 74-233 m/s, the relative deviation between the predicted results and numerical results is less than 10% for models 2 and 4 and is large for models 1 and 3. Under the pressure of 0.1-2.1 MPa, the windage loss increases linearly with the increase of the pressure. The predicted result of model 2 is closer to its numerical result, with a maximum relative deviation of 1.44%when the Reynolds number ranges from 10⁴ to 6×10⁴, and the predicted result of model 4 is closer to its numerical result, with a maximum relative deviation of 6.15% when it is higher than 6×10⁴. Flow field results show that there are periodic Taylor vortices in gap, the velocity pattern is divided into three regions in radial direction, and the vorticity near the wall is greater than that at the centerline. The study results provide the basis on selecting windage loss model and offer reference to the development of more accurate models.