基于车流密度的道路噪声源动态辐射模型

相较于车流相对稳定的高速公路而言,城市交通流因上下班高峰、红绿灯、交叉路口等影响,具有明显的波动性。现有噪声预测模式中,声源辐射模型采用小时流量及设计速度作为独立变量,车速与车流量没有关联,仅适用于测量常年平均声级,不能正确反映城市道路噪声的动态变化特征。文章对交通流模型进行了调查,以行车速度与车流密度制约关系为基础,结合道路车辆的物理模型及声源辐射模型,建立以车流密度为变量的噪声源动态声源辐射计算模型,描述城市道路交通噪声辐射声级随车流密度的动态变化特征,与已有模型进行对比并通过实测,验证了新模型能更好地反映城市道路车辆声源辐射声级的变化情况。

Dynamic emission model of road noise source based on the traffic density

Apart from relatively stable traffic on the highway, the road traffic flow in urban area shows strong fluctuation due to the influence of rush hours, traffic lights and the intersections. Hourly flow and default designing speed are used as two separate parameters in the existing noise prediction models, which is only adapted to the measurement of long time average sound level, and so the existing noise prediction models cannot describe the dynamic characteristic of road traffic noise in urban areas. Currently the existing traffic models are investigated with the combination of physical model of vehicles and the sound emission model, a dynamic emission model of road noise source is proposed based on the traffic density. Compared with the existing models, this model describes the dynamic characteristic of traffic noise emission level with the changes of traffic density and better reflects the fluctuation of the traffic noise with the demonstration of the experimental data.