锥形轴承腔油气两相流动与换热数值研究

Numerical Study of Oil-Air Two-Phase Flow and Heat Transfer in Tapered Bearing Chamber

关键词:  航空发动机  轴承腔  油气两相流  锥形结构  传热传质

Key words:  Aero-engine  Bearing chamber  Two phases（air-oil）flow  Tapered structure  Heat and mass transfer

摘要:

轴承腔壁面两相流动与换热是轴承腔精细化设计的基础，与腔壁结构密切相关。针对具有典型锥形结构特征的轴承腔内的油气两相流动和换热问题，基于相体积分数（Volume of Fluid，VOF）两相流动模型，通过与圆柱形轴承腔进行对比，参数化分析获得了锥形结构对流动及换热的影响，使用无量纲分析的方法，建立了适用于该锥形轴承腔常见工况范围内的对流换热准则式。研究表明：锥形轴承腔壁的换热量略小于柱形腔，锥形腔壁换热量随着发动机主轴转速的升高而增加，随着供油量的增加线性增加，随着封严气流量的增加先减小后增大。

Abstract:

The two-phase flow and heat transfer on the wall of bearing chamber are the basis of the fine design of the bearing chamber and are closely related to the structure of the bearing chamber wall. Aiming at the two-phase flow and heat transfer of a bearing chamber wall with typical tapered structure， based on the VOF two-phase flow model， through a comparison with the cylindrical bearing chamber and a parametric analysis， the effects of the tapered structure on heat transfer were obtained. This paper uses the non-dimensional analysis method to establish the convective heat transfer criterion formula that is suitable for the tapered bearing chamber in the range of common operating conditions. Studies have shown that the heat transfer of the tapered bearing chamber wall is slightly less than that of the cylindrical cavity. The heat transfer rate of the tapered chamber wall increases with the increase of the engine main shaft rotating speed， linearly increases with the increase of the oil supply， and decreases first and then increases with the increase of the sealed air flow.