GOALI: Transient Dynamics of Torsional Vibration Absorbers

这个GOALI项目的目标是研究装有扭转振动吸收器的转子系统的瞬态动力学。对这些系统的更好理解与它们在采用停缸的汽车发动机中的实施直接相关。由于振动问题，在低转速端，可以停用气缸的发动机转速范围受到限制。如果这些振动可以减少，气缸停缸的操作包络线可以扩大，从而导致显著的燃料节省和更低的排放。离心摆式减振器在提供所需的减振方面显示出很大的前景，并正在考虑在这些发动机中使用。PI已经对这些吸收器的稳态操作有了全面的了解，但是它们在汽车发动机中的实施取决于它们在瞬态操作条件下的令人满意的行为。因此，这项工作的主要目标是建立一个基本的了解转子的瞬态动力学与系统的摆锤吸振器，以及系统参数影响这种行为的方式。这项工作的结果将扩大我们的基本知识基础的行为的振动吸收系统，更一般地说，关于瞬态响应的系统的对称性。调查将涉及分析、实验以及与工业界的合作。分析将涉及建模，微扰方法，以及不变流形和对称理论的概念。将针对不同的减振器调谐和阻尼条件以及各种类型的瞬态条件进行实验。结果是根本利益，因为它们涉及的瞬态响应问题，包括稳定性问题，经常被忽视的研究周期性强迫动力系统。研究结果还将允许开发可用于汽车发动机减振器系统设计的指南。为了应对更广泛的影响，PI将担任密歇根州立大学高中工程学院的讲师三年。大约四分之一的报名参加这个夏季外展计划的人来自代表性不足的群体。能源问题将是该计划的主要焦点话题，拟议的研究将在此背景下进行描述。工业PI将通过提供先进发动机技术的一般工业观点来影响计划内容。此外，该材料将被纳入现有的课程，特别是作为学习瞬态振动响应相关问题的重要性的动机。此外，为了充分实现这项研究的好处，研究结果将通过出版物和会议报告广泛传播，从而使所有感兴趣的汽车制造商都能获得。

The goal of this GOALI project is to investigate the transient dynamics of rotor systems fitted with torsional vibration absorbers. An improved understanding of these systems is directly relevant to their implementation in automotive engines that employ cylinder deactivation. The range of engine speeds over which one can deactivate cylinders is limited on the low-rpm end by vibration problems. If these vibrations can be reduced, the operating envelope for cylinder deactivation can be expanded, resulting in substantial fuel savings and lower emissions. Centrifugal pendulum vibration absorbers show great promise for providing the required vibration reduction, and are being considered for use in these engines. The PIs have developed a thorough understanding of the steady-state operation of these absorbers, but their implementation in automobile engines depends on their satisfactory behavior under transient operating conditions. Thus, the primary goal of this work is to develop a fundamental understanding of the transient dynamics of rotors fitted with systems of pendulum absorbers, and the manner in which system parameters affect this behavior. The results of this effort will expand our fundamental knowledge base about the behavior of vibration absorber systems and, more generally, about the transient response of systems with symmetries. The investigation will involve analysis, experiments, and collaboration with industry. The analysis will involve modeling, perturbation methods, and concepts from invariant manifolds and symmetry theory. Experiments will be carried out for different absorber tuning and damping conditions and various types of transient conditions. The results are of fundamental interest since they involve questions of transient response, including stability issues that are often overlooked in studies of periodically forced dynamical systems. The results will also allow for the development of guidelines that can be used in the design of absorber systems for automotive engines.In order to address broader impacts, the PIs will serve for three years as instructors for the Michigan State University High School Engineering Institute. About a quarter of the enrollment for this summer outreach program comes from under-represented groups. Energy issues will be the primary focus topic of the program, and the proposed research will be described in that context. The industrial PI will influence program content by providing a general industrial perspective on advanced engine technology. In addition, the material will be incorporated in existing courses, specifically as motivation for the importance of studying problems relevant to transient vibration response. Also, in order to fully realize the benefits of this investigation, the results will be made widely available through publications and conference presentations, thereby making them accessible to all interested automotive manufacturers.