基于DoE的车用消声器优化设计

针对某乘用车消声器在发动机转速1 500～3 000 r/min范围内尾管噪声偏大的问题,应用GT-Power软件建立发动机及排气系统模型,并对该模型进行了试验验证。应用DoE方法找到了对消声器性能影响较大的参数,建立了消声器性能综合评价体系。依据运行工况及指标的重要程度为各转速下的评价指标设计了相应的权重,通过多目标优化计算得到了最优化的消声器结构参数。优化后消声器的模拟计算结果表明,在发动机转速1 500~3 000 r/min范围内,尾管总噪声和2阶噪声有较大程度上的降低。     

基于抗车辙功能的高模量沥青混凝土应用研究

针对沥青路面的车辙损坏,通过掺加改性剂PR／RA以提高沥青混凝土模量,达到有效提高路面抗车辙能力的目的。介绍了高模量沥青混凝土（HMAC）的研究成果,如提出基于抗车辙功能高模量沥青混凝土的合理设置层位和模量值的合理取值范围、抗车辙能力强的高模量沥青路面结构组合,以及高模量沥青混凝土路面典型结构等。并结合试验路实体工程,提出高模量沥青混凝土路面的施工工艺与质量控制技术。     

乌克兰汽车市场现状及我国汽车进入当地对策

东欧市场已经成为我国重要的整车出口市场,我国汽车企业急需了解东欧汽车市场及政策信息、文章通过介绍乌克兰汽车产业、市场和相关政策情况,深入分析我国汽车产品在乌克兰市场情况,提出了企业应加强售后服务体系建设和加快整车本地化生产等建议,对帮助我国汽车企业开拓乌克兰市场具有非常重要的指导意义.     

汽车动力性的计算机模拟

建立了汽车动力性的目标函数,给出了其求解方法,提出了动力性的约束条件,利用VB语言实现了汽车动力性的计算机模拟。     

集装箱船机舱风机噪声治理

针对船舶机舱轴流风机产生的气动噪声,进行产生机理分析,分别对不同位置风机噪声采取不同的治理方案以及相应的降噪效果计算方法,有效控制了风机噪声,同时对机舱风机、风管设计提出了建议。     

节流孔板的流场噪声耦合分析及改型设计

针对某型汽轮发电机组油管路振动噪声大的问题,利用数值仿真方法对油管路节流孔板进行流动与噪声耦合计算分析,结果表明故障原因是节流孔板处产生了汽蚀现象。在此基础上,对节流孔板结构形式进行改型优化,得到节流降压及噪声性能优越的半圆角型节流孔板结构,这是因为圆角导流作用有效减弱了孔板处的流动剪切作用,进而降低了噪声,并防止了汽蚀现象的发生。     

The role of household members in transporting adults with disabilities in the United States

Because of certain requirements under US federal law, many studies have been published in recent years on the role of fixed-route transit and paratransit in meeting the travel needs of persons with disabilities. Although persons with disabilities are several times more likely to take rides from household members than to take public transit, little research has been conducted to explore the circumstances under which such rides are given or taken. To address this gap in literature, this study examines the role of household members in transporting persons with disabilities in contemporary America. It explores how the circumstances for the ride takers may change in the future, identifies future challenges in providing mobility to persons with disabilities, and examines ways to meet those challenges. Using nationwide data from the 2009 National Household Travel Survey, the study compares the rides taken by persons with disabilities from household members with trips made by other travel modes, the persons who take rides with those who do not take rides, and the drivers who provide rides with those who do not provide rides. Probit models are used for the comparisons. Implications of the findings are discussed in light of potential demographic changes in the future, especially the growth of single-person households and the consequent loss of household support for transportation. Due to similarities in circumstances in other developed countries, an international context to the study is also provided.     

Noise effects and real estate prices: A simultaneous analysis of different noise sources

We simultaneously analyze the effects of alternative noise sources to isolate their relative harms. This research adds to the literature, which has only analyzed one noise source or has aggregated the noise levels of different sources. Flight noise had the most negative effect on housing prices, and road and train noises had similar but smaller effects.     

潜水器纵倾调整系统噪声分析及控制建议

针对潜水器纵倾调整系统,从噪声源种类、机理和传递途径入手,分析该系统在2种工作工况下的有效噪声源.通过对有效声源进行内部振动加速度测试和外部水噪声测试,结合已有研究成果,逐步分析该系统对潜水器水噪声的影响,并据此提出潜水器纵倾调整系统在各工况下的低噪声控制建议.     

汽车可靠性工程数据分布规律的模糊模式识别法

根据汽车可靠性工程数据,对其进行可靠性定量分析时,应该首先判别可靠性数据的分布规律。汽车可靠性工程数据的分布规律具有模糊集合的性质。本文探索了用模糊模式识别法识别汽车可靠性工程数据的分布规律,简单易行,实用。