Further Computational Investigations Into Aero-Engine Bearing Chamber Off-Take Flows
Further Computational Investigations Into Aero-Engine Bearing Chamber Off-Take Flows
复制标题
对航空发动机轴承室排气流的进一步计算研究
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
H. Morvan
中科院分区：
文献类型：
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作者：
A. Robinson;C. Eastwick;H. Morvan
在航空发动机轴承腔内，油被提供给部件以润滑和冷却。这种油必须有效地从腔室中除去（清除），以确保它不会过热和降解。轴承室通常包含一个带出口管的油底壳部分，出口管通向清除泵。本文计算分析了一个简化的水槽截面的几何形状，这里简单地由一个有壁的斜面上的径向进水口构成。本文继承了GT2008-50634中提出的工作。在以前的论文中，它表明，简单的重力排水从一个静态的液体头部可以准确地建模，类似于深坑的情况下，喜欢在集成齿轮箱。本文的工作将表明，垂直于运动膜的流的排水是可以模拟的。这种情况类似于变速器轴承室的布置。模拟的情况是一个带有圆形起飞口的壁重力驱动薄膜在飞机上运行，这重复了类似于GT2008-50632报告的实验工作。商业计算流体动力学（CFD）代码Fluent 6[1]已被用于建模，使用Hirt和Nichols[2,3]的流体体积（VOF）方法来捕获清除管系统中膜运动和两相流的物理特性。使用表面张力[4]和锐化算法[5]来补充自由表面的表示和相关效果。最初的CFD研究得到了实验工作的支持和验证，这里仅简要描述，因为它主要用于支持CFD方法。这个案例已经被完整地建模，并且使用了一个平行于通道壁的平面中心的对称平面。本文包括网格划分方法的细节，所采用的边界条件，这将被证明是至关重要的准确建模，以及建模假设。最后，总结了对建模案例观察到的流模式的见解。本文进一步强调了CFD是一种很有前途的分析轴承室扫气气流的方法，尽管它仍然相对昂贵。劳斯莱斯公司版权所有©2010
Within an aero-engine bearing chamber oil is provided to components to lubricate and cool. This oil must be efficiently removed (scavenged) from the chamber to ensure it does not overheat and degrade. Bearing chambers typically contain a sump section with an exit pipe leading to a scavenge pump. In this paper a simplified geometry of a sump section, here simply made of a radial off-take port on a walled inclined plane, is analysed computationally. This paper follows on work presented within GT2008-50634. In the previous paper it was shown that simple gravity draining from a static head of liquid cold be modelled accurately, for what was akin to a deep sump situation fond in integrated gear boxes for example. The work within this paper will show that the draining of flow perpendicular to a moving film can be modelled. This situation is similar to the arrangements found in transmission bearing chambers. The case modelled is of a walled gravity driven film running down a plane with a circular off-take port, this replicates experimental work similar to that reported in GT2008-50632. The commercial computational fluid dynamics (CFD) code, Fluent 6 [1] has been employed for modelling, sing the Volume of Fluid (VOF) approach of Hirt and Nichols [2, 3] to capture the physics of both the film motion and the two phase flow in the scavenge pipe system. Surface tension [4] and a sharpening algorithm [5] are used to complement the representation of the free surface and associated effects. This initial CFD investigation is supported and validated with experimental work, which is only depicted briefly here as it is mainly sued to support the CFD methodology. The case has been modelled in full as well as with the use of a symmetry plane running down the centre of the plane parallel to the channel walls. This paper includes details of the meshing methodology, the boundary conditions sued, which will be shown to be of critical importance to accurate modelling, and the modelling assumptions. Finally, insight into the flow patterns observed for the cases modelled are summarised. The paper further reinforces that CFD is a promising approach to analysing bearing chamber scavenge flows although it can still be relatively costly.Copyright © 2010 by Rolls-Royce plc