关键词：汽车排放、植树、CO2扩散、计算流体动力学分析(CFD)、标量混合分析
摘 要：由于燃料的使用，交通已经成为世界上二氧化碳排放的主要来源之一。在路边种植树木以减少空气中的二氧化碳水平，因为树木有能力吸收二氧化碳用于光合作用过程。如果二氧化碳的扩散集中在树木周围，这种能力将最大化。然而，在这方面，与以前的研究有一些不同的结果。一些研究结果发现树木可以增加二氧化碳浓度，反之亦然。因此，本研究旨在利用真实的3D环境评估路边植树对CO2扩散的影响。本研究采用的方法是CO2排放分析，获取CO2的总量。然后，利用计算流体动力学(CFD)分析方法，模拟了研究区无树木和有树木时CO2的扩散情况。但是，由于空气和CO2的混合，此模拟使用标量混合分析。同事考虑到了一些条件，如建筑物特征、树木特征和环境条件。结果表明，树木可以降低车速，增加路边的CO2浓度，但可以降低道路上的CO2浓度。在0.9-1m/s范围内，植树可使流速降低4.3%。这种情况会增加路边的二氧化碳浓度。树木可以使路边右侧的二氧化碳浓度增加25%，左侧的二氧化碳浓度增加10%。
Abstract: Transportation has become one of the most significant contributors to CO2 in the world because of its fuel usage. Trees are planted on the roadside to reduce levels of CO2 in the air because trees have the ability to absorb CO2 to be used in the photosynthesis process. This ability will be maximized if the dispersion of CO2 is concentrated around the tree. However, there are some differing results from previous studies regarding this. Some research results have found trees can increase CO2 concentration and vice versa. Accordingly, this study aims to evaluate the effect of tree planting on the roadside in dispersing CO2 using a real 3D environment. The methods used in this research are CO2 emission analysis to obtain the amount of CO2. Then, Computational Fluid Dynamics (CFD) analysis is used to simulate the dispersion of CO2 in the study area both without trees and with trees. However, due to the mixing of air and CO2, this simulation uses a scalar mixing analysis. Some conditions are considered, such as the characteristics of buildings, the characteristics of trees, and environmental conditions. The result indicates that trees can decrease the velocity and increase the concentration of CO2 on the roadside but decrease CO2 concentration on the road. Tree planting can decrease the velocity by 4.3% in the value range 0.9-1 m/s. This condition increases CO2 concentration on the roadside. Trees can increase CO2 by 25% on the right of a roadside and increase CO2 concentration by 10% on the left side.
Key: Vehicle emission, Tree planting, Dispersion of CO2, Computational Fluid Dynamics analysis (CFD), Scalar mixing analysis
全文: DOI