GOALI: Transient Dynamics of Torsional Vibration Absorbers

这个GOALI项目的目标是研究装有扭转吸振器的转子系统的瞬态动力学。提高对这些系统的理解直接关系到它们在采用汽缸停用的汽车发动机中的实施。由于振动问题，发动机转速的范围在低转速端是有限的。如果能够减少这些振动，则可以扩大汽缸停用的操作范围，从而节省大量燃料并降低排放。离心摆减振器显示出提供所需的减振的巨大希望，并且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运行有了透彻的了解，但它们在汽车发动机中的实现取决于它们在瞬态运行条件下的令人满意的行为。因此，这项工作的主要目标是发展与钟摆吸收系统的转子瞬态动力学的基本理解，以及系统参数影响这种行为的方式。这项工作的结果将扩展我们关于减振器系统行为的基本知识基础，更广泛地说，关于具有对称性的系统的瞬态响应。调查将包括分析、实验和与工业界的合作。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。实验将进行不同的吸收器调谐和阻尼条件和各种类型的瞬态条件。这些结果具有根本性的意义，因为它们涉及瞬态响应问题，包括在周期性强迫动力系统研究中经常被忽视的稳定性问题。研究结果还将允许制定可用于汽车发动机吸收系统设计的指导方针。为了解决更广泛的影响，这些pi将在密歇根州立大学高中工程学院担任三年的讲师。参加这个暑期拓展项目的学生中，约有四分之一来自代表性不足的群体。能源问题将是该计划的主要焦点主题，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视角来影响节目内容。此外，这些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力。此外，为了充分实现这项调查的好处，研究结果将通过出版物和会议报告广泛提供，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.