基于非定常涡升力的压气机转子/静子气动布局理论与实验研究

There are two kinds of lift mechanism. The one is to obtain airfoil lift with attached flow on the basis of Kutta condition, the lift coefficient was generally around 0.6-1.3, and the other is unsteady vortex lift by the relative motion between bodies, which was discovered by studying insect flight, the instaneous lift coefficient is as high as 8-12. It is found that almost all flight vehicles and turbomachinery are based on the application of the first kind of lift principle. Currently, micro-flight vehicle is receiving great attention; their aerodynamic design completely relies on the exploitation of unsteady vortex lift. It is obvious that the application of unsteady vortex lift principle in turbomachinery will be a meaningful and challenging issue. In the present investigation, it is suggested that the unsteady vortex lift will be realized by the interaction between the rotor and controlable stator. For this purpose, the relevant investigation deals with the development of high accuracy scheme which aims to simulate moving boundary problem. On the basis of this, a computational model will be proposed to simulate the unsteady vortex lift produced by rotor/stator. The experimental work will be also conducted in order to make qualitative comparison with the numerical data. The above investigation may rich the technical approach to reach the objective of higher aerodynamic loading and higher performance of compression system in aviation propulsion system.

迄今人类发现的升力机制有两种：第一种是基于附体流动获取升力，可获得的升力系数大致在0.6-1.2之间，几乎目前所有飞行器及广泛应用的叶轮机械都是依据这一原理设计的；第二种升力机制是生物学家研究昆虫飞行发现的 "非定常涡升力"机制，其最大升力系数可达8-12。目前，国内外正在竭力发展的微小飞行器正是利用了"非定常涡升力"这一飞行原理。然而，如何将这一升力机制应用到叶轮机则是一个亟需研究的问题。本项目提出通过转子/静子非定常相互作用来实现非定常涡升力机制的应用。研究内容包括，运动边界流动的高精度数值模拟方法，在统一坐标下求解转子/静子相互作用的物理模型。此外，将构建以转子/静子为单元的试验平台，实验研究非定常涡升力对压气机性能的影响。这些工作的完成不仅会拓宽非定常涡升力的应用范围，也会对航空推进器压缩系统如何提高叶片负荷，进而增加推重比提供新的选择途径。

迄今人类发现的升力机制有两种：第一种是基于附体流动获取升力，可获得的升力系数大致在0.6-1.2 之间，几乎目前所有飞行器及广泛应用的叶轮机械都是依据这一原理设计的；第二种升力机制是生物学家研究昆虫飞行发现的 “非定常涡升力”机制，其最大升力系数可达8-12。目前，国内外正在竭力发展的微小飞行器正是利用了“非定常涡升力”这一飞行原理。然而，如何将这一升力机制应用到叶轮机则是一个亟需研究的问题。本项目提出通过转子/静子非定常相互作用来实现非定常涡升力机制的应用。研究内容包括，运动边界流动的高精度数值模拟方法，在统一坐标下求解转子/静子相互作用的物理模型。此外，将构建以转子/静子为单元的试验平台，实验研究非定常涡升力对压气机性能的影响。这些工作的完成不仅会拓宽非定常涡升力的应用范围，也会对航空推进器压缩系统如何提高叶片负荷，进而增加推重比提供新的选择途径。按任务书承诺研究内容及结点目标,本项申请首先通过对转子/静子相互作用物理机制的研究，分别从理论和实验两个方面探讨实现非定常涡升力在压缩系统中利用的途径。该项工作涉及到运动边界的高精度算法，在统一坐标下转子/静子计算模型的建立，关键实验样机的原理性试验等多方面的内容。具体的研究成果包括：（1）发展了已有的运动边界数值模拟平台，实现了在统一的正交坐标系下求解转子静子干涉非定常流动；（2）数值模拟研究验证了缩小转子/静子轴向间距可以产生非定常涡升力，提高级压比；（3）通过轴流泵实验验证了数值模拟所预测的轴向间距对转子/静子级气动性能的影响，并通过PIV流场显示实验，进一步揭示了非定常流动与气动性能之间的关联；（4）数值模拟初步探索了运用转子/调制静子机构加强非定常涡升力的可能性；（5）在叶轮机稳定性问题上取得了几方面的进展。