无轴向通流对转轴间的流动与传热特性

Flow and Heat Transfer Characteristics InterCounter-Rotating Shaft Without Axial Flow

关键词:  对转轴间  卡门三层结构  对转环腔速度分布  比拟理论  壁面换热系数

Key words:  Inter counter-rotating shaft  Kanman three-layer structure  Velocity distribution of counter-rotating annulus  Analogy theory  Wall heat transfer coefficient

摘要:

为研究航空发动机对转轴间的流动与换热，建立了无轴向通流的对转环腔湍流边界层的修正卡门三层结构速度分布模型。基于该速度分布模型并依据动量传递与热量传递的比拟理论，推导了外轴内壁面换热努塞尔数的表达式及准则关系式。与CFD数值计算的速度分布、外轴内壁面换热努塞尔数进行对比验证，结果表明，对转环腔湍流边界层的修正卡门三层结构模型给出了一致的速度分布和换热规律。理论与CFD计算得到的外轴内壁面换热努赛尔数在低旋转雷诺数下符合较好，高旋转雷诺数下偏离不超过20%。

Abstract:

The flow and heat transfer inter the counter-rotating shaft is focused in this work. The modified velocity distribution model for flow in the counter-rotating annulus inter shaft without axial flow is established based on Karman three-layer structure of the turbulent boundary layer. The formula and correlation equation for the Nusselt number of outer shaft surface is derived using the velocity distribution model following the analogy theory of momentum transfer and heat transfer. In contrast to the velocity distribution and the heat transfer Nusselt number of outer shaft surface obtained by CFD，the results using the modified Karman three-layer structure model for flow in the counter-rotating annulus inter shaft are in good agreement with CFD. The velocity distribution and the heat transfer Nusselt number of outer shaft surface gotten by the heat transfer Nusselt number of outer shaft surface obtained by CFD and theoretic deduction is consistent in low rotational Reynolds number, the maximum deviation is no more than 20% in high rotational Reynolds number.