%0 Journal Article
%T MR- and ER-Based Semiactive Engine Mounts: A Review
%A Mohammad Elahinia
%A Constantin Ciocanel
%A The M. Nguyen
%A Shuo Wang
%J Smart Materials Research
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/831017
%X Hybrid propulsion technologies, including hybrid electric and hydraulic hybrid, equip vehicles with nonconventional power sources (in addition to the internal combustion engine) to provide higher fuel efficiency. However, these technologies tend to lead to higher levels of noise, vibration, and harshness in the vehicles, mainly due to the switching between the multiple power sources involved. In addition, the shocks and vibrations associated with the power sources switching may occur over a wide range of frequencies. It has been proven that passive vibration isolators (e.g., elastomeric and hydraulic mounts) are unable to mitigate or totally isolate such shocks and vibrations. Active mounts, while effective, are more complex, require significant power to operate, and can lead to system instabilities. Semiactive vibration isolators have been shown to be as effective as active mounts while being less complex and requiring less power to operate. This paper presents a review of novel semiactive shock and vibration isolators developed using magnetorheological and electrorheological fluids. These fluids change their yield stress in response to an externally applied magnetic and electric field, respectively. As a result, these fluids allow one to transform a passive hydraulic vibration isolator into a semiactive device. 1. Introduction In recent decades, the soaring price of fossil fuels has impacted negatively the popularity of the vehicles with internal combustion (IC) engines. This is due, primarily, to the fact that the emissions from IC engines account for a large percentage of the carbon dioxide stored in the atmosphere [1]. In addition, the materials conventionally used for making the cars have become scarcer, and recycling of used cars raised concerns about pollution and waste management. Furthermore, the increasing number of cars worsened the congestion problem and road quality. Among these causes, the gas price and the emission are considered the most important, since they directly affect the wealth of the society and the sustainability of the earth, respectively. Electric propulsion systems, on the other hand, received more attention as potential candidates for the future of transportation. Nevertheless, since the full electric technology is still in the developing phase and very expensive for regular passenger cars, a great number of modifications to the conventional vehicles have been made in order to achieve higher fuel efficiency and lower emission rate. One of the technologies presented by Kumagai et al. [2] is variable cylinder management
%U http://www.hindawi.com/journals/smr/2013/831017/