峡谷型交叉口内机动车尾气污染的动态数值模拟

项目名称： 峡谷型交叉口内机动车尾气污染的动态数值模拟

项目编号： No.50808181

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 蔡铭

作者单位： 中山大学

项目金额： 20万元

中文摘要： 由机动车尾气引发的城市空气污染问题现已越来越严重，特别在道路交叉口处，由于车流汇集拥堵，加上城市高楼峡谷不利于污染物扩散，交叉口的机动车尾气污染问题尤为突出。而受气象条件和峡谷建筑物影响的机动车尾气污染现象本来就相当复杂，再考虑交叉口信号控制和动态交通流的影响，峡谷型交叉口内机动车尾气污染的动态数值模拟具有很大的理论价值和实用价值。 相对于大部分不考虑尾气动态排放的研究，本研究采用动态交通流仿真软件模拟车辆不同的运行状态，通过参数归一和数据映射，结合微观尾气排放模型得到信号交叉口动态尾气源，然后建立多车道峡谷型交叉口物理模型，用计算流体力学方法模拟机动车尾气在城市风环境中的动态扩散过程，以得到污染物浓度的时空分布，并通过风洞实验和实地监测进行验证。研究结果可揭示交通流变化及交通控制策略等因素对峡谷型交叉口内污染物浓度分布的影响规律，为掌握和控制交叉口尾气污染提供理论基础和技术手段。

中文关键词： 机动车尾气污染；动态排放源；扩散数值模拟；峡谷型交叉口；信号控制

英文摘要： Urban air pollution caused by vehicle exhaust emission is becoming more and more serious, especially in road intersection, which is due to the traffic congestion and street canyon effects. The pollution problem of vehicle exhaust emission affected by meteorological conditions and canyon buildings is already complicated, if we take the intersection signal variation and dynamic traffic flow impact into consideration, the problem is become more challenging and significant. Different from most studies that neglect the dynamic emission characteristics of vehicle exhaust, our research will focuse on dynamic numerical simulation of vehicle exhaust emission in street canyon intersection. Specifically, dynamic traffic simulationsoftware is used to simulate various running state of vehicles. By parameters normalization and data mapping, dynamic emission sources in intersection can be obtainedusing comprehensive modal emission model. Then a physical model of street canyon intersection is established, and computational fluid dynamics method is applied to simulate the dynamic process of pollutant dispersion with the physical model. Finally, temporal and spatial distribution of pollutant concentrations can be obtained, and the results will be verified by wind-tunnel experiments and field monitoring. The research can reveal the relationship between dynamic traffic flow, traffic control strategies and distribution of pollutant concentrations in street canyon intersection, and provide a theoretical basis and technological method to control vehicle emission in intersection.

英文关键词： Vehicle exhaust pollution; dynamic emission source; dispersion numerical simulation; street canyon intersection; signal control