BUOYANCY-INDUCED FLOW AND HEAT TRANSFER IN COMPRESSOR ROTORS
BUOYANCY-INDUCED FLOW AND HEAT TRANSFER IN COMPRESSOR ROTORS
复制标题
压缩机转子中的浮力诱导流动和传热
DOI：
10.1115/1.4038756
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发表时间：
2018
影响因子：
1.5
通讯作者：
J. Owen
中科院分区：
文献类型：
--
作者：
Hui Tang;M. R. Puttock;J. Owen
燃气涡轮发动机压气机转子内部的浮力引起的流动和传热影响压气机盘的应力和径向增长，并且它还导致通过盘中心的冷却空气的轴向通流中的温度升高。进而，盘的径向增长影响旋转压缩机叶片与周围的静止壳体之间的径向间隙。该间隙的计算是极其重要的，特别是在航空发动机中，其中压力比的增加导致叶片尺寸的减小。在本文中，一个出版的理论模型的基础上浮力引起的层流Ekman层流的旋转磁盘上扩展到包括从压缩机护罩和强迫对流之间的孔的磁盘和轴向通流的层流自由对流。预测的热传递从这三个表面，然后用于计算的通流的温度上升。预测的温度和努塞尔数进行了比较，在多腔压气机钻机的测量，主要是良好的协议是实现了一系列的Rossby，雷诺数和Grashof数的代表性的航空发动机压气机。由于圆盘之间流体核心的可压缩性效应，如前所述，增加转速可导致核心温度增加，从而降低圆盘和护罩的努塞尔数。
The buoyancy-induced flow and heat transfer inside the compressor rotors of gas-turbine engines affects the stresses and radial growth of the compressor disks, and it also causes a temperature rise in the axial throughflow of cooling air through the center of the disks. In turn, the radial growth of the disks affects the radial clearance between the rotating compressor blades and the surrounding stationary casing. The calculation of this clearance is extremely important, particularly in aeroengines where the increase in pressure ratios results in a decrease in the size of the blades. In this paper, a published theoretical model—based on buoyancy-induced laminar Ekman-layer flow on the rotating disks—is extended to include laminar free convection from the compressor shroud and forced convection between the bore of the disks and the axial throughflow. The predicted heat transfer from these three surfaces is then used to calculate the temperature rise of the throughflow. The predicted temperatures and Nusselt numbers are compared with measurements made in a multicavity compressor rig, and mainly good agreement is achieved for a range of Rossby, Reynolds, and Grashof numbers representative of those found in aeroengine compressors. Owing to compressibility effects in the fluid core between the disks—and as previously predicted—increasing rotational speed can result in an increase in the core temperature and a consequent decrease in the Nusselt numbers from the disks and shroud.