Search Results

This paper summarizes the attributes of automotive exhaust system and provides a guideline for exhaust system design, analysis and development. The exhaust system has various attributes including vibration, acoustics or noise, durability and thermal distribution, flow and power loss, emission, in addition to its interface with vehicle. This paper describes all these attributes and the corresponding performances, and develops criteria for each of the attributes. The paper also describes the interfaces between the exhaust system and powerplant with body structure.

Vibrations of a cup-shaped rotor in a bushless DC motor are investigated. The 4-phase motor has 12 pole pieces in the stator which is surrounded by a cylindrical, cup-shaped rotor with 14 magnets. The strong, pulsating magnetic forces acting on the rotor result in strong vibrations. Finite Element Analysis is used to analyze the vibrational pattern of the rotor. The impact of small changes in the dimensions of the rotor on its vibrational frequencies is also investigated. Details of FEA modeling will be presented and its predictions will be compared with the experimental data.

The objective of this paper is to explore the dynamic features of vibrations and instability in automotive front end accessory drive belt system. To address this issue, a non-linear model of a moving beam with friction coupling on elastic foundation is developed. The model takes into account of a variety of nonlinear effects, including the contact stiffness nonlinearity, nonlinearities associated with the friction, tensioned parametric excitation, as well as the beam geometry nonlinearity. Different nonlinear properties are examined, and numerical simulations are conducted to investigate the system and to correlate with the experimental results. The major contributors to the dynamic contact instability are illustrated and are attributed to modal coupling and/or negative damping.