摩托车底盘测功机阻力的设定

摩托车工况法排放污染物测试及整车底盘动力性能测试都需要进行摩托车道路行驶阻力的测定及底盘测功机上摩托车行驶阻力的设定，利用惯性滑行法测定和计算摩托车道路行驶阻力，并进行底盘测功机上带车滑行试验调整行驶阻力系数，可以保证底盘测功机能够较精确地模拟摩托车实际道路行驶阻力。     

风洞法测量汽车道路行驶阻力

阐述了风洞法测量汽车行驶阻力的基本原理,并进行了风洞法和道路滑行法的对比测试试验。结果表明,风洞法和道路滑行法测得的汽车行驶阻力数值十分接近,测得的行驶阻力相对偏差在4%以内,循环能量差在±5%以内,证明了风洞法的有效性。不同车速下的CD~*A值差异对行驶阻力的影响极小,风洞法中的等速法与减速法相比,等速法的试验结果更接近道路滑行结果。     

汽车道路滑行阻力的研究

基于汽车道路滑行原理,建立汽车道路滑行阻力的计算模型,分别对车辆不同状态进行道路滑行试验,得到滑行阻力曲线,分析影响车辆滑行阻力的主要因素,对比了滑行法和标准查表法得到的阻力曲线,结果显示滑行法得到的道路阻力更能真实反映车辆道路行驶实际情况。     

汽车行驶阻力模型参数的确定

在分析汽车行驶阻力特性后,结合仿真分析与试验设置等具体应用需要,建立起含有3个未知系数的行驶阻力模型。基于非线性最小二乘法拟合原理,应用数值计算方法求解微分方程,并进行优化迭代;充分利用汽车滑行过程数据记录中的丰富信息,快速有效地求解出汽车的行驶阻力模型。     

重型商用车滑行阻力系数的测定与研究

针对道路滑行试验方法下汽车道路行驶阻力系数的准确获取问题,提出基于时间法开展空挡下道路滑行试验研究汽车道路行驶阻力。阐述了试验车辆依据时间法在道路上开展滑行试验及获取试验数据的方法,并利用最小二乘法曲线拟合的方法对试验数据进行处理,从而计算出空气阻力系数和滚动阻力系数。结果显示,滑行时间法测定的道路行驶阻力更能真实反映车辆道路行驶实际情况,具有较好的实用性。     

轻型汽车道路行驶阻力的测量及影响因素分析

分析了轻型汽车道路行驶阻力的数学模型,并在阐述滑行法测量道路行驶阻力的试验方法后,通过多组对比试验得出：轮胎和环境温度是影响滑行时间t的主要因素;尤其是试验环境温度与标态温度相差越大,行驶阻力相对偏差越大。并对如何通过提高滑行时间的统计精度p来尽量减少滑行次数提出几点措施。     

车辆行驶阻力测量风洞法与滑行法对比试验研究

GB 18352.6—2016《轻型汽车污染物排放限值及测量方法(中国第六阶段)》中提出了风洞法测量道路行驶阻力,为验证风洞法测量结果的准确性,针对2辆样车进行了实车试验,并与滑行法进行对比。结果表明,风洞法测得的行驶阻力与滑行法测量结果的偏差在±1.25%以内,风洞法与滑行法行驶阻力测量结果循环能量差在±1%以内,满足国Ⅵ排放标准中两种方法之间的循环能量差在±5%以内的要求,验证了风洞法测量结果的准确性及测量设备的有效性。     

道路行驶阻力的滑行法测量及其在底盘测功机上的设定

阐述了滑行法的基本原理和用滑行法测量道路行驶阻力的规定、数据处理，分析了道路滑行试验的几个影响因素，概述了底盘测功机上道路阻力设定原理和常用的设定方法、校核方法，比较了欧洲、日本、美国滑行法测量和设定道路行驶阻力的一些规定。     

基于轻型车国六标准的道路滑行阻力试验

针对轻型汽车污染物排放限值及测试方法(中国第六阶段),分析了道路滑行阻力的试验方法。结合某在研车型试验数据,对比了国六标准与国五标准中道路滑行阻力试验方法的区别。并设计了道路行驶阻力处理软件,介绍了该软件的主要内容和使用方法,利用该软件可快速计算出整车道路滑行阻力曲线。     

摩托车行驶性能曲线图的绘制

摩托车的行驶性能曲线图，最基本的图形是摩托车阻动力－－行驶阻力平衡图，在已知摩托车有关发动机特性曲线的发动机特性曲线的情况下，可用公式计算驱劝力和行驶阻力，而用整车直接在底盘模拟试验台上测试和用ＣＺＹ－１型摩托车车载路试仪通过道路试验测取驱动力和行驶阻力则更方便和准确。在此基础上，将驱动力图和行驶阻力图绘制在同一个坐标系中，邓完成摩托车行驶性能曲线图。     

汽车滑行阻力系数的测定方法

通过matlab的符号微分方程解法求出汽车滑行运动方程,在给定的阻力系数范围内找到计算数据和采样曲线之间有最小平均偏差的阻力系数,也就是最能拟合滑行采样数据的滚动阻力系数和风阻系数,这种方法的可操作性强而且计算精度可以通过对阻力系数的细分大小来控制。     

乘用车滑行阻力与传动系阻力的研究

从汽车滑行运动微分方程入手,利用滑行数据,提出了一种计算汽车滑行阻力与速度关系的新算法,又分别计算得到试验乘用车滑行过程中的滚动阻力、空气阻力和传动系阻力,并且分析了传动系阻力随速度的变化规律。     

测定汽车滑行阻力系数的方法

从汽车滑行运动微分方程入手，经过积分推导出滚动阻力系数和空气阻力系数与滑行初速度、滑行总时间和滑行总距离之间的关系，用滑行过程中3个瞬时点的记录参数组成方程组，再用MATLAB求方程组的数值解，即可求出汽车的滚动阻力系数和空气阻力系数。本方法只需一次滑行试验，既方便易行，又比较准确。     

A study on the resistance force and the aerodynamic drag of Korean high-speed trains

The resistance force as well as the aerodynamic drag of Korean high-speed trains including two commercial trains, the KTX and the KTX-Sancheon (KTX-II) and two experimental trains, the HSR-350X and the HEMU-430X have been studied comprehensively. To deduce the aerodynamic drag of the trains, the coefficients of the Davis equation, which is a universal formulation to represent the resistance to motion of the train, have been calculated using the coasting test method and analysed in comparison with those by empirical prediction methods. In case of HEMU-430X train, the equations of resistance to motion have been calculated by an alternative regression method that is established in this study. The results show that the suggested method can successively yield the resistance to motion equation from the coasting test measurements with varying air density by separating the aerodynamic drag from the total resistance of train. It also prevents from improper coefficients which are occasionally taken by normal regression method in irregular coasting condition. After yielding the aerodynamic drag of the trains from the resistance to motion equations, characteristics of the aerodynamic drag have been analysed and compared between the trains.     

ATV车架焊接工艺流程分析

ATV车架焊接的好坏与车架材料、工装固定、焊丝种类、焊接电流和焊接顺序等密切相关,焊接前可结合CAE分析和残余应力分布的预判来确定车架材料及焊接顺序;在进行跑车试验前,先检查焊接质量,如焊接接头所包括的焊缝、熔合区和热影响区等,以设定整个工艺流程;用材料试验法对关键点的焊接接头进行检查,可对焊接工艺给出合理判断.     

用滑行试验法测定汽车空气阻力系数研究

测定汽车的空气阻力系数对开发汽车产品具有非常重要的意义，较详细地介绍了用道路上的滑行试验测定汽车空气阻力系数的理论基础，道路试验方法及数据处理方法，并给出了松花江中意HFJ6351C型微型客车的空气阻力系数的试验数据，研究表明，采用滑行试验法测定汽车空气阻力系数远比采用风洞法简单方便，且费用低廉。     

A study on the stability of a motorcycle wheel–swingarm suspension with chain transmission

The present study describes a possible driving mechanism for a self-excited oscillation observed in motorcycle dynamics, often referred to as chatter. This phenomenon, affecting the performance of road racing motorcycles, has been simulated in straight running braking manoeuvres with multibody motorcycle models. It involves rear suspension bounce and driveline oscillation in the frequency range between 17 and 22?Hz. A simplified model of a motorcycle rear suspension with chain transmission is proposed and its stability in equilibrium configurations is studied via eigenvalue analysis. The sensitivity with respect to all its governing parameters is analysed by means of stability maps and the self-excitation mechanism is explained with the aid of energy balance analysis and phase diagrams. It is found that the key role for the instability onset is played by the gradient of the nonlinear characteristic slip function of the tyre.     

Experimental and numerical analysis of the influence of tyres’ properties on the straight running stability of a sport-touring motorcycle

The behaviour of a motorcycle on the road is largely governed by tyre properties. This paper presents experimental and numerical analyses dealing with the influence of tyre properties on the stability of weave and wobble in straight running. The final goal is to find optimal sets of tyre properties that improve the stability of a motorcycle. The investigation is based on road tests carried out on a sport-touring motorcycle equipped with sensors. Three sets of tyres are tested at different speeds in the presence of weave and wobble. The analysis of telemetry data highlights significant differences in the trends of frequency and damping of weave and wobble against speed. The experimental analysis is integrated by a parametric numerical analysis. Tyre properties are varied according to the design of experiments method, in order to highlight the single effects on stability of lateral and cornering coefficient of front and rear tyres.