车轮空气动力学外流场数值模拟模型研究

应用计算流体动力学及有限元方法创建钢制车轮外流场的仿真模型.采用了两种不同形式模型方案,解决了复杂结构车轮轮廓边界层划分及车轮接地区域网格的生成问题.采用RNG k-ε湍流计算模型,分析车轮的气动阻力系数变化规律,为基于空气动力学的车轮设计提供理论依据.HT5H     

机车车轮多轴疲劳强度安全评定的研究

使用ANSYS8.0软件对高速列车车轮进行了三维有限元分析,计算出车轮在直线、曲线和道岔条件下牵引、制动共6种工况时孔边薄弱部位的应力,分别通过Mises等效平均应力方法、Sines平均主应力方法和应力分量中考虑平均应力方法计算出应力在极值位置时的等效应力幅、等效平均应力,从而进一步算出车轮的安全系数,对其疲劳强度进行评定,并对3种方法进行了比较研究。     

基于ANSYS的弹性车轮模态分析

指出弹性车轮因具有很多优点而在现代轻轨车辆上得到了广泛的应用。利用有限元分析软件ANSYS对弹性车轮进行了模态分析,得出了其固有频率和振型,并与刚性车轮进行了比较,为弹性车轮的动力学分析奠定了可靠的基础。     

高速动力车车轮强度分析的工程方法

基于国际铁路联盟相关标准确定了高速动力车车轮强度分析的计算载荷工况,提出了一套建立车轮有限元模型和模拟运行状态下的车轮应力分布规律、静强度和疲劳强度的数值分析方法,为车轮结构设计和强度分析提供了可靠的理论依据,满足工程技术的实际需求。     

城市轨道交通线路轨底坡对钢轨磨耗的影响

采用城市轨道车辆标准型面车轮与标准型面钢轨相匹配,建立不同轨底坡的车轮与钢轨三维弹塑性接触有限元模型,根据计算得出的接触斑面积、接触应力等结果分析轨底坡对钢轨磨耗的影响。计算分析结果表明：无轨底坡时,车轮与钢轨的接触位置总是靠近钢轨内侧,导致钢轨内侧磨耗严重;随着钢轨轨底坡的增大,轮轨的接触位置逐渐向钢轨外侧移动,接触应力也发生变化,1／40轨底坡下轮轨接触应力较小,钢轨磨耗较慢;单独增大内轨轨底坡对减缓钢轨侧磨非常有利。     

LQ6105柴油机气缸体模态试验研究及静、动态有限元分析

内燃机产品的设计、改型都应进行静态计算及动态分析。目前,常用的且行之有效的方法有：有限元计算分析和试验模态分析。有限元计算分析的主要特点是：其计算分析结果的可靠与否主要取决于计算的数学模型。本文将有限元计算分析与试验模态分析结合使用。利用试验模态分析低频段主模态参数较为可靠的特性来修改有限元计算的数学模型,使有限元单元划分方案及边界条件更接近实际部件的结构。进而对ＬＱ６１０５增压中冷柴油机缸体进行静、动态分析,验证了本文方法的有效性,并获得满意的效果。     

机车轮对加装扣环后的模态分析

通过建立机车车轮的有限元模型,在考虑机车车轴、轮心、轮箍3部分装配应力以及车轮运行时速的基础上,对加装扣环的车轮与未加装扣环的车轮进行了模态分析,提取了前5阶固有频率和振动型态,并进行了对比分析,确定了扣环槽的存在对车轮结构模态的影响,同时也排除了机车轮对系统与机车悬挂系统之间发生共振现象的可能性,为机车轮对加装扣环方案在动力学方面提供了理论依据。     

面向对象有限元程序设计

提出了一种实用的面向对象有限元程序设计方法。使用UML统一建模语言详细地描述了程序主要对象模型的结构,在此框架结构下运用C 语言编制了有限元结构计算程序,利用该程序进行了工程实例计算分析,验证了本文方法的正确性。     

柴油机连杆有限元接触分析算法的探讨

利用ANSYS有限元分析软件对6113型柴油机连杆进行了有限元接触分析算法的探讨。根据连杆的受载状况,建立了按多体接触的三维模型,模拟了连杆零部件之间的接触,用有限元的方法对设计的连杆进行了结构强度计算分析。     

车用涡轮增压器压气机叶轮强度计算与分析

通过对车用增压器压气机叶轮内应力特点的分析,确定了叶轮强度的计算方法,介绍了利用有限元分析软件对叶轮内部应力进行分析的过程,并就强度分析中的关键步骤和技术难点进行了讨论。通过有限元计算结果分析,找到了车用增压器压气机叶轮应力集中的位置,研究了如何利用几何参数的修改来减小集中应力。计算并讨论了叶片气动载荷和温度场对压气机叶轮应力的影响,建立了车用增压器压气机叶轮强度分析的过程和方法。     

不退轮箍加装扣环的方法及效果

介绍了对带轮箍的机车车轮实施不退轮箍加装扣环的可行性、实施过程及效果,指出不退轮箍加装扣环能满足轮对装配技术标准,方案是可行的。     

Practical thermal performance correlations for molecular sieve and silica gel loaded enthalpy wheels

The central thrust of this research was to develop practical enthalpy wheel effectiveness correlations useful for enthalpy wheel integrated systems design and analysis. In this research, enthalpy wheel performance data generated using established fundamental enthalpy wheel models were statistically analyzed. And then, first order linear regression equations were derived to estimate the enthalpy wheel sensible and latent effectiveness at normal operating rotational speeds (i.e. over 20 rpm). The two most common desiccant materials, silica gel and molecular sieve on aluminum substrate, were analyzed. Each correlation relates the enthalpy wheel sensible and latent effectiveness as a function of six parameters; incoming outdoor air and exhaust air temperature and relative humidity, face velocity, and air flow ratio. The enthalpy wheel leaving air conditions can then be simply estimated by employing the practical effectiveness correlations. Predicted effectiveness values corresponded well with published manufacturer’s data and existing fundamental enthalpy wheel models.     

DF4D、DF11型机车整体车轮剥离的原因分析及对策

根据南昌机务段DF4D、DF11型机车整体车轮剥离的情况,对其原因从金相组织、工作状态等方面进行了分析,并针对如何减少机车车轮剥离提出了一些看法和措施。     

Comparative analysis of different design of rotary dehumidifier

A one‐dimensional mathematical model has been developed to do the comparative analysis of four design of the desiccant wheel. The mathematical model has been validated with experimental results and shows good agreements with experimental results. In this study, a two‐sector desiccant wheel is modified into a three‐sector wheel by introducing a purge section in the desiccant wheel. Similarly, a four‐sector desiccant wheel is reformed into a six‐sector wheel by installing two purge section in the desiccant wheel and comparative study of these designs have been carried for given ranges of operating conditions. The effect of purge conditions has been also investigated and found that in all operating conditions six‐sector design is a better choice for optimum MRC and ?T.     

水泵机组增设惯性飞轮与电动机起动转矩复核

高扬程电泵站的水锤压力削减和倒转转速的控制,除目前的传统方法外,在泵组上增设惯性飞轮,增加GD2值,也许是一种好办法.本文粗浅地从三个方面讨论泵组增设惯性飞轮后的相关问题,即控制关闭时间计算;泵组电动机起动转矩核算;惯性飞轮尺寸计算确定.     

车轮淬火加热过程温度场的数值模拟

根据马钢车轮淬火加热炉的实际状况,建立了车轮淬火加热过程温度场计算模型。应用该模型对某规格车轮的淬火加热过程温度场进行了模拟,并应用在线测温系统对该规格车轮淬火加热过程的温度变化进行了实测,结果与实测结果吻合较好。通过模拟发现,该规格车轮现行加热时间过长,有很大的压缩空间。     

轮轨非对称接触及形面损伤问题分析

随着列车运行速度的提高,车轮形面损伤问题也日益严重。车轮形面损伤分为踏面剥离、车轮失圆和轮缘磨耗等类型。车轮形面损伤后会导致车辆的不平稳运行,使车辆一方面产生低频、中频和高频的振动,影响车辆的运行平稳性和乘坐舒适性,另一方面会引起车辆内部的噪声,车轮损伤严重时甚至会直接导致车辆脱轨事故的发生。车轮损伤问题是由轮轨接触非对称现象所引起的,轮轨非对称接触分为对称踏面与非对称钢轨的接触、非对称踏面与对称钢轨的接触以及非对称踏面与非对称钢轨的接触三种类型。当车轮形面或钢轨损伤后,就会导致轮轨非对称接触的发生,而轮轨非对称接触又会加剧车轮形面的损伤。为了提高车辆的动力学性能和运行稳定性,必须避免轮轨强非对称接触的发生。     

Thermal models of railroad wheels and bearings

The rolling surface for railroad wheels can be a heat source that may have an impact on the performance of the wheel bearing. In this study, experimental data from an electrically-heated railroad wheel set is analyzed by constructing thermal models of the wheel set. A steady finite-element model, a steady-analytical model, and a transient lumped-parameter model are discussed. Model parameters are determined from careful comparisons with the experimental data. The lumped-parameter model given here is intended as a simple predictive tool for determining when wheel heating caused by rail operations will have an impact on bearing temperature. The model parameters found in this study will also be useful as experimentally-validated boundary conditions in ongoing finite-element studies of heated wheels.     

INFLUENCE OF ELEVATED PRESSURE ON SORPTION IN DESICCANT WHEELS

Rotary desiccant wheels have been employed to dry pressurized air streams. In these systems, depending on the moisture content in the air stream and the operating pressure, condensation can occur in the regeneration portion of the wheel. In this article, a numerical method using an implicit finite-difference scheme is developed and applied that enables condensation to be detected and simulated in the regeneration portion of a desiccant wheel operating at high pressures. Using this model, performance analysis of desiccant wheel under these conditions is investigated. It is found that, depending on the value of the separation factor and regeneration temperature, condensation could occupy as much as 40% of regeneration section of the wheel. In this region, regeneration of the desiccant is not possible and usually dehumidification of regeneration air occurs. Also, as the operating pressure increases, the adsorption and desorption characteristics are dramatically affected and the optimum separation factor of desiccant material increases with operating pressure.     

用间隙元求解枞树形叶根轮缘的接触问题

就汽轮机枞树形叶根齿面与轮缘的接触状态进行了研究.通过在接触面上施加间隙元来解决叶根轮缘的接触问题,计算结果表明每一对叶根齿面的承载比直接取决于叶根齿与轮缘的初始接触情况,而每一对齿的内弧齿面的承载比与背弧齿面的承载比的变化则还与叶型相对叶根的位置有关.