基于驾驶负荷模型的高原弯坡组合路段安全性分析与评价

为了解驾驶员安全舒适度评价指标(驾驶负荷)在高原公路弯坡路段的变化特征,利用生物反馈仪等相关设备,在海拔大于3 000~5 000 m的高原公路选取符合标准的弯坡路段62段进行行车试验。定量分析了驾驶负荷与海拔、高原公路弯坡路段线形组合值之间的变化关系;并且建立了相关模型。结果表明,驾驶员在高原公路弯坡路段行车过程中,驾驶负荷受到海拔与弯坡路段线形组合值的双重影响;驾驶负荷随着海拔的升高而增大;上下行过程中,驾驶负荷随着弯坡路段线形组合值的增大而增大;在海拔与弯坡路段线形组合值的共同作用下,驾驶负荷变化更加明显,海拔越高、弯坡线形组合值越大,驾驶负荷越大。     

Comfort of Light-weight Wool and Wool Blend Woven Fabrics

The comfort of the light-weight woven fabrics was investigated by conducting the wear trials under the controlled climatic conditions. The wear trial under the neutral environmental conditions showed that the lightweight wool and wool blend fabrics are generally less comfortable than the silk fabric, cotton poplin and polyester/cotton poplin fabrics tested in this study. The main shortcoming in terms of comfort for these lightweight wool fabrics is the prickle. Besides, the fabric softness was found to be a very important factor influencing the comfort of the clothing worn next to the skin.     

汽车平顺性分析与评价系统软件

对汽车的平顺性进行仿真预测、结构参数优化选择,在新产品设计、旧车改进及汽车使用维护具有重要的作用和意义.采用汽车总的振动舒适度作为汽车的评价及优化指标,并设计了相应的软件,为该类车型的设计及改进提供了理论指导.     

轮毂电机电动汽车轮内悬置系统设计与优化

为了改善轮毂电机驱动电动汽车簧下质量变大导致的垂向振动负效应问题,优化汽车的平顺性,以自主研发的可实现四轮独立驱动的轮毂电机电动汽车为实验对象,设计了一种可安装于电动轮内的轮毂电机悬置系统.提出在电动轮内的特定位置加装橡胶衬套的悬置系统方案,使轮毂电机的定子和转子与簧下质量实现弹性隔离.建立具备电动轮内悬置系统的整车动...     

A Generalized Comfort Function of Subway Systems Based on a Nested Logit Model

With rapid urbanization,subway systems are widely acknowledged as one of the best solutions to urban transportation problems.The operators or managers of subway systems should pay more attention to passenger＇s perceptions of service quality to maintain its competitive position.Taking the traffic state,efficiency,and environmental impact into consideration,the concept of generalized comfort is proposed in this paper.Based on a nested logit model,the selection probability for each factor in a generalized comfort function can be estimated using a nested structure.A certain factor is considered to be more significant in a generalized comfort function than others,when the corresponding probability of this factor is higher in value.Using stated preference and revealed preference data about passenger travel behavior obtained from the Beijing subway,the parameters of generalized comfort function are estimated by maximum likelihood techniques.     

变风量HVAC系统模型定性分析

利用能量与质量守恒定律，通过建立包括通风，室内围护结构、户外环境条件等诸因素的非线性时延控制数学模型，给出了保证系统有唯一正平衡态及系统全局渐近稳定的充分条件，分析表明，系统的平均点与各环境参数有关，在平衡状态下，室内气温约为28℃，最后借助一个实例，说明本文的结果可以帮助人们根据环境特点，去选择适当的HVAC控制系统。本文提供的方法同样适用于PI，PID控制系统的分析。     

Heat balance modelling

The only way to describe the effects of the thermal environment on the human body completely is to do it by means of an energy balance equation. In such an equation all relevant meteorological parameters, behavioral characteristics (activity and clothing) and body measurements can be considered. Using Fanger's comfort equation and the models MEMI and IMEM as examples, the problems of energy balancing and ways of solving them are described. The value of energy balance models is documented by examples from the field of application.     

Indoor climate

In industrialized countries most of the time is spent indoors. The basic ambient parameters for a thermally comfortable indoor climate are air temperature, air velocity, humidity and radiation pattern. Besides the thermal component, the concentrations of air pollutants in the indoor air are also of importance for wellbeing and health. Their levels are influenced both by the outdoor concentrations and the indoor emissions. The increasing use of air conditioning systems in many cases has not resulted in improving the indoor climate but causes a wide range of irritations and health problems summarized as sick building syndrome.     

寒冷地区民用住宅冬季自然通风数值分析

为研究不同开窗通风模式对寒冷地区冬季室内环境参数的影响,采用CFD中的Realizable k-ε模型对兰州地区某住宅在考虑非稳定传热情况下的室内流场、温度场、热舒适性进行了数值分析,得到了既保证室内采暖温度要求又改善了室内空气品质的三种冬季自然通风模式。比较了三种通风模式下不同房间内的流场、温度场的分布特征。对不同通风模式下室内热舒适性的评价结果表明:室内整体上偏凉。     

基于CFD仿真技术对某敞篷车外流场的优化

通过CFD方法对某敞篷车与硬顶车进行空气动力学仿真分析,对比流场发现敞篷车座舱内部形成的局部涡流区是造成周围气流回流从而降低乘坐舒适性与增加风阻系数的主要原因.通过延长挡风玻璃、提升后背高度、调整挡风玻璃倾角在33°附近,可显著减少回流到座舱的气流以提升乘坐舒适性,并降低气流在座舱及后背处发生的分离,有效降阻达16%,获得较好的空气动力学特性.