Research on Transfer Characteristics of Engine Vibration Load to Cabin Seat

发动机振动载荷向客舱座椅传递特性研究

School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China

Received: 20 April 2020

Abstract

Aeroengine is one of the main vibration sources that affect the passenger comfort. The contribution of engine vibration to the vibration response of seat will provide basic data for the design of airliner vibration comfort and engine vibration isolation installation. Firstly, the dynamical model of middle fuselage compartment with double-beam wing was established. Then, based on the typical vibration load spectrum of the engine, the acceleration responses of the key nodes of the wing beam and the seat connection points were analyzed, and the main path of engine vibration transmission to seats was identified. Finally, using operational transfer path analysis (OTPA) method, the contribution of engine front and rear mount point vibration to the vertical acceleration response of the seats was compared, and the three-dimensional information of wing structure vibration transmission was explored. The results show that the fundamental frequency component of low-pressure rotor of engine vibration has the greatest impact on the seat vertical response under takeoff and cruise conditions, the contribution rate of the front mount point vibration is about 71% and 67% respectively. However, the fundamental and its 3/2 times frequency components of high-pressure rotor have relatively large impact on the seats vertical response under flight idle state, and the contribution rate of engine front mount point vibration is about 45% and 60% respectively. In addition, the engine vibration is mainly transmitted from the wing front beam to the seat vertical response. The vertical direction of the wing beam and the rotation direction around the fuselage are also the main direction of vibration transmission.

摘要

航空发动机是影响客机乘坐舒适性的主要振源之一，研究发动机振动对座椅振动响应的贡献将为客机振动舒适性设计及发动机隔振安装提供基础数据。为此，建立了客机中机身舱段-双梁机翼动力学模型，基于发动机典型振动载荷谱，仿真分析了机翼前后梁关键节点和座椅连接点的加速度响应，辨识了发动机振动向客舱传递的主路径。基于工况传递路径分析(OTPA)方法，比较研究了发动机前后挂点振动对客舱不同座椅垂向加速度响应的贡献量大小；探索了翼梁结构振动传递的三维信息。结果表明：在起飞和巡航状态下，发动机振动低压转子基频分量对座椅垂向响应影响最大，此时发动机前挂点激励的贡献率分别约为71%和67%；而空中慢车状态下，发动机振动的高压转子基频分量及其3/2倍频分量对座椅垂向响应的影响相对较大，且发动机前挂点激励的贡献率分别约为45%和60%；另外，发动机振动主要通过机翼前梁向座椅连接点垂向传递，且机翼前后梁垂向、绕机身纵向和横向转动方向也是振动传递主要方向。