环形交叉口机动车油耗与污染物排放特性的数值模拟

On motor vehicle fuel consumption and pollutant emission features at roundabout crosscorners based on a numerical simulation

为了解环交口在不同交通条件下机动车油耗与污染物排放特性,以SIDRA公司INTERSECTION软件为研究工具,分别研究了不同交通总量、不同流向组成条件下,环交口机动车平均油耗和CO2、NO、CO等污染物排放量的分布规律,以及不同交通总量条件下,环交口与信控交叉口机动车平均油耗和污染物排放量的分布规律。结果表明,随交叉口交通总量增加,环交口机动车平均油耗和污染物排放量也呈逐渐增加趋势。当左转交通比例增加时,环交口机动车油耗和污染物排放量均呈增加态势;当右转交通比例增加时,环交口机动车油耗和污染物排放量则呈降低趋势。交叉口饱和度低于0. 46时,环交口机动车平均油耗和CO2排放量低于信控交叉口;交叉口饱和度低于0. 58时,环交口机动车NOx和CO等污染物排放量低于信控交叉口。因此,在交通负荷不大的情况下,环交口较信控交叉口具备更好的节能减排效果。

The present paper has done a numerical simulation inhoping to fully comprehend the characteristic features of the vehicle fuel consumption and its pollutant emission under the various traffic conditions of the roundabout street corners. The said simulation scheme can be divided into 2 groups,the first group of which mainly deals with the various features of the fuel consumption and pollutant emission of the motor vehicle at the street roundabout under the various traffic volumes and different cornerturning traffic intensities. However,the stress of the second group scheme is to make a comparison between the distribution characteristic features of the fuel consumption and the pollutant emission between the roundabout section and the signal-controlling intersection under the different traffic interactive conditions.The analysis tool we have adopted for the topic study is the software known as the Sidra Intersection. The simulation results help us to gain the following conclusions. First of all,with the increase of the total traffic volume of the roundabout,the average fuel consumption of the motor vehicles and the emission of CO2,NOx,CO and other pollutants also show a gradually increasing trend. Moreover,it is often the case that the roundabouts have to be done via the 2-lane and the 4-lane,when the traffic volume exceeds 3 500 veh/h,with the actual motor vehicle fuel consumption and the pollutant emission tending to increase abruptly.And,in such a situation,the proportion of traffic turning would have a certain impact on the motor vehicle fuel consumption and pollutant emission. However,when the ratio of the left-turning traffic increases,the motor vehicle fuel consumption and the pollutant emission of the roundabout both have to increase. Nevertheless,on the contrary,when the ratio of the right-turning traffic increases,the fuel consumption and pollutant emission would have to decrease,too. Thus,eventually,when the saturation is lower than 0. 46,the average fuel consumption and the vehicle’s CO2 emissions at the roundabout would have to be lower than those at the signals-controlled intersection. What’s more,if the saturation is lower than 0. 58,the emission of the pollutants such as NOxand CO at the roundabout would have to be lower than that at the signals-controlled intersection. In other words,under the condition of the small traffic load,the roundabout of the vehicle may have to enjoy a chance for better energy thrift and emission reduction than that of the merely signals-controlled intersection.