汽车理论课件_汽车理论（英文）.pptVIP

《Elementary Vehicle Dynamics 》（《汽车理论》） Preface What’s the aim of this course To find out the reasonable method to design and use vehicle according to the relationship among the parameters of structure and performance of vehicle. （通过车辆结构参数与性能之间的关系，找到正确设计汽车的方法和合理使用汽车的途径） Chapter one –Acceleration Performance §1.1 Evaluation Index（评价指标） 1.Maximum Vehicle Speed (Velocity)最高车速——uamax (km/h): （1）Definition：The maximum speed which the vehicle can get under good and flat road with rated load （额定载荷). （2）Actual Measurement of uamax 2. Acceleration Ability（加速能力） （1）The acceleration ability for starting(原地起步加速能力) Test Condition : Full engine power （油门全开）; Optimal shift point between gears（最佳换档时机） which are from low gear （第Ⅰ档） for start-up to high gear （最高档） for fuel economy. Evaluation Index—T T is the time needed by the vehicle to accelerate from 0 to 0.8Uamax under the above test condition or the time needed to pass through a fixed distance （400 m or ? mile(402.5m)）. （用Ⅰ档起步，按最佳换档时间，逐次换至高档，油门全开，以最大加速度行驶，全力加速至 0.8uamax所需时间，或通过某 一预定距离所需时间） （2）The acceleration ability for high speed driving(超车加速能力) Test condition: Full engine power ; High gear（最高档）or inferior high gear（次高档） Evaluation index——T T is the time need to accelerate from the minimum stable speed of high gear(最高档的最小稳定车速）to 0.8Uamax or the time needed to pass through a fixed distance （400 m or ? mile）. (在直接档工作时，油门全开，由该档的最小稳定车速全力加速至 0.8Uamax所需时间，或通过某一预定距离所需的时间） 3.Maximum Gradeability of Vehicle—— imax（最大爬坡度） （1）Definition： The maximum grade which the vehicle can climb in the first gear（Ⅰ档） under good road condition with fully rated load（额定满载）. i=tgα EQ140 imax=28% EQ240 imax=58% α=30° （2）Actual Measurement of imax §1.2 Driving Mechanics of Vehicle To analyze the balance between Total Roads（行驶阻力）and Tractive Force（驱动力）along one degree of freedom（自由度） that is longitudinal direction（纵向）. 1.Tractive F