滑油射流冲击旋转壁面的流动换热数值模拟研究

Numerical Study of Flow and Heat Transfer Characteristics of Oil Jet Impingement on Rotating Wall

关键词:  航空发动机  轴承  流动  换热  射流  数值模拟

Key words:  Aeroengine  Bearing  Flow  Heat transfer  Jet  Numerical simulation

摘要:

为研究射流流速与发动机转速对轴承腔旋转壁面冷却效果的影响，采用数值模拟方法研究了滑油射流冲击旋转壁面的流动与换热特性，重点关注和分析了中高转速下射流雷诺数Re_j和旋转雷诺数Re_ω对于滑油流动和壁面整体及局部传热的影响。为体现不同工况对壁面换热的影响，分别采用了壁面平均传热量、壁面努赛尔数、局部平均努塞尔数进行了综合换热分析。研究结果表明，随着射流流速增加，壁面附着油量增多，壁面平均传热量与局部换热分别增加约32%和40%；而随着壁面转速增加，壁面附着油量下降，壁面平均传热量减少约13%，局部换热增加约62%。

Abstract:

In order to investigate the effects of jet velocity and engine rotation speed on the cooling effect of the bearing chamber rotating wall， a numerical study was performed to investigate the flow and heat transfer characteristics of the oil jet impinging on the rotating wall， with the main concern on the effects of jet Reynolds number Re_j and rotating Reynolds number Re_ω on oil flow and the overall and local heat transfer of the wall at medium and high rotation speeds. So as to reflect the effects of different working conditions on the wall heat transfer， the average heat transfer of the wall， the Nusselt number of the wall， and the local average Nusselt number were respectively used for the comprehensive heat transfer analysis. The results show that with the increase of jet velocity， the amount of oil attached to the wall increases， and the average heat transfer and local heat transfer increase by 32% and 40%， respectively. With the increase of the wall rotating speed， the amount of oil attached to the wall decreased， the average heat transfer on the wall decreased by about 13%， and the local heat transfer increased by about 62%.