A Computational Parametric Analysis of the Vibration of a Three-Spool Aero-Engine Under Multifrequency Unbalance Excitation
A Computational Parametric Analysis of the Vibration of a Three-Spool Aero-Engine Under Multifrequency Unbalance Excitation
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DOI：
10.1115/1.4002664
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发表时间：
2011-07
影响因子：
1.5
通讯作者：
P. M. Hai;P. Bonello
中科院分区：
文献类型：
--
作者：
P. M. Hai;P. Bonello
在航空发动机组件中集成挤压膜阻尼器（SFDs）是一种极具成本效益的方法，可以在其他轻微阻尼的结构中引入阻尼。然而，它们的部署需要仔细的不平衡响应计算，适当考虑sfd的非线性，特别是当它们没有集中弹簧支持时。直到最近，由于通常需要考虑大量的装配模式，这种计算是令人望而却步的。作者通过新颖的脉冲接收法（IRM）和接收谐波平衡法（RHBM）克服了这一问题，分别有效地解决了时域和频域的非线性问题。这些方法在实际的双轴发动机上得到了验证，对单频不平衡激励（单转子不平衡）和多频不平衡激励（双转子不平衡）均有效。在本文中，这些方法应用于一个现实的三轴发动机，目的有两个：(i)提出一些初步的参数化研究结果，进入一个三轴航空发动机组件；（ii）提出一种技术，利用IRM和RHBM在MFU激励下产生速度响应（从所有三个转子）与转子之间的实际速度关系。后一种技术是必要的，因为速比将沿着实际的速度特性变化，作者以前已经解决了恒定速比条件下的双轴MFU问题。这里使用的方法是通过一种近似速度特性的方法，其中速度比是低整数的比率，使使用RHBM能够完成通过IRM获得的（稳态）时间瞬态解。参数研究表明，将简单的碰撞弹簧支承应用于选定的非支承SFDs并进行轻微密封，将对具有大转子的航空发动机的动态响应产生有益的影响。
The integration of squeeze-film dampers (SFDs) in aero-engine assemblies is a highly cost-effective means of introducing damping in an otherwise lightly damped structure. However, their deployment requires careful unbalance response calculations that take due account of the SFDs' nonlinearity, particularly when they are unsupported by a centralizing spring. Until recently, such calculations were prohibitive due to the large number of assembly modes that typically need to be considered. This problem has been overcome by the authors through the novel impulsive receptance method (IRM) and the receptance harmonic balance method (RHBM), which efficiently solve the nonlinear problem in the time and frequency domains, respectively. These methods have been illustrated on a realistic twin-spool engine and have been shown to be effective for both single frequency unbalance excitation (unbalance on a single rotor) and multifrequency unbalance (MFU) excitation (unbalance on both rotors). In the present paper, the methods are applied to a realistic three-spool engine and the aims are twofold: (i) to present some preliminary results of a parametric study into a three-spool aero-engine assembly and (ii) to propose a technique that makes use of both IRM and RHBM in producing the speed responses under MFU excitation (from all three rotors) with a realistic speed relation between the rotors. The latter technique is necessary since the speed ratio will vary along a realistic speed characteristic and the authors have previously solved the twin-spool MFU problem under a constant speed ratio condition. The approach used here is to approximate the speed characteristic by one in which the speed ratios are ratios of low integers, enabling the use of RHBM to finish off (to steady-state) time-transient solutions obtained through IRM. The parameter study shows that the application of simple bump-spring supports to selected, otherwise unsupported, SFDs along with slight sealing should have a beneficial effect on the dynamic response of aero-engines with heavy rotors.