基于底盘测功机的摩托车耐久性和工况排放试验中冷却风机出口风速随距离衰减的研究

摩托车国Ⅲ工况排放测试和耐久性测试中，摩托车要在底盘测功机上跟踪规定的曲线行驶，风机模拟道路行驶中的自然风冷却车辆，速度满足风速等于车速。由于从风机出口断面到摩托车发动机有一定距离，随着距离的增加，出口风速、风量会发生衰减和扩散，这样，到达发动机的风速必然小于车速，致使冷却效果下降，模拟效果不佳，长时间运行还会对发动机、催化转化器产生损害，影响排放结果。

Study on the Reduction of Wind Speed at Outlet of Inter-cooling Fan During Motorcycle Durability and Operation Mode Tests Based on Chassis Dynamometer

During the tests on emission and durability of motorcycle,which is Euro-Ⅲcompliant. Motorcycle will operate on the stipulated curve on chassis dynamometer.The fan imitate the natural during the operation to cool the motorcycle.With the increase of the distance between the cross-section of the outlet of fan,the speed and volume of wind will be reduced,this gives rise to the poor cooling effect.And this will even damage the engine and catalytic converter after the long-time operation.