车辆工程毕设英文翻译

车辆工程毕设英文翻译内容摘要：

vibration, reducing the various parts of the ChuanZhen capacity, an increase of parts at or above the critical frequency of vibration isolation capacity. At present, some countries have designed an engine experts active vibration isolation system to reduce engine vibration, in order to achieve the purpose of noise reduction. (2) intake noise Engine intake noise is one of the main noise source, the Department of the engine noise of air power, with the engine speed increases to strengthen. Nonsupercharged engine intake noise major ponents, including the cyclical pressure fluctuation noise, vortex noise, the cylinder of the Helmholtz resonance noise. Diesel engine supercharger intake noise mainly from the turbocharger pressor. Two stroke engine noise from the Roots pump. In this regard, the most effective method is the use of intake muffler. There is a resistive type muffler (absorption type), resistant muffler (expansion type, resonance type, interferencetype and porous decentralized) and the posite muffler. To bine with the air filter (that is in the air filter on an additional resonance chamber and soundabsorbing material, for example, type R3238) has bee the most effective intake muffler, muffler volume of more than 20dBA. Chassis Noise (1) Department of exhaust noise Department of the chassis exhaust noise is the main noise sources, mainly from the exhaust pressure pulsation noise, air flow through the valve seat when issued by eddy current noise, because of boundary layer airflow disturbance caused by noise and exhaust Office jet noise position. Designed to optimize the performance of a good muffler, to reduce car noise are one of the important means. Optimize design method has acoustic finite element method and acoustic boundary element method, but is still in its infancy. Muffler to avoid the transmission characteristics and vibration characteristics of coupled mufflers are designed to be focused on solving a problem. Secondly, to reduce exhaust noise and improve power is also a pair of contradictions, because to reduce exhaust noise and lower exhaust back pressure on the design of the exhaust pipe has a diameter of conflicting demands, the former requires a smaller diameter, which is opposite . In this regard, the use of parallel flow path of the dual function muffler, at reduced air pressure and reduce noise to be effective. In addition, the engine exhaust manifold to the muffler inlet pipe section, the use of flexible pipe vibration, noise reduction effect can be reduced to about 7dBA. (2) power train noise Powertrain noise from the vibration caused by 变速齿轮 meshing and rotating shaft vibration. General measures taken are: First, choose lownoise transmission, engine and gearbox are two and the main red。