Advanced modeling of the absorption enhancement of black carbon particles in chamber experiments by considering the morphology and coating thickness  

作　　者：Xiaodong Wei Jianlin Hu Chao Liu Xiaodong Xie Junjie Yin Song Guo Min Hu Jianfei Peng Huijun Wang 

机构地区：[1]Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Collaborative Innovation Center of Atmospheric Environment and Equipment Technology,School of Environmental Science and Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,China [2]Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Key Laboratory of Meteorological Disaster(Ministry of Education),Nanjing University of Information Science and Technology,Nanjing 210044,China [3]Nansen−Zhu International Research Centre,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [4]East China Air Traffic Management Bureau CAAC,Shanghai 200335,China [5]State Key Joint Laboratory of Environmental Simulation and Pollution Control,International Joint Laboratory for Regional Pollution Control(IJRC)(Ministry of Education),College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China [6]Tianjin Key Laboratory of Urban Transport Emission Research&State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control,College of Environmental Science and Engineering,Nankai University,Tianjin 300071,China

出　　处：《Frontiers of Environmental Science & Engineering》2024年第9期129-142,共14页环境科学与工程前沿（英文）

基　　金：supported by the National Key R&D Program of China(2018YFC0213800);the National Natural Science Foundation of China(Grant No.42021004);the open fund of the Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control(China)(KHK1908).

摘　　要：Measurements studies have shown that the absorption of radiation by black carbon(BC)increases as the particles age.However,there are significant discrepancies between the measured and modeled absorption enhancement(E_(abs)),largely due to the simplifications used in modeling the mixing states and shape diversities.We took advantage of chamber experiments on BC aging and developed an efficient method to resolve the particle shape based on the relationship between the coating fraction(ΔD_(ve)/D_(ve),0)and fractal dimension(D_(f)),which can also reflect the variations of D_(f)during the whole BC aging process.BC with externally and partly mixed states(0≤ΔD_(ve)/D_(ve),0≤0.5)can be considered to be uniformly distributed with the D_(f)values of 1.8–2.1,whereas the Df values are constrained in the range 2.2–2.8 for fully mixed states(ΔD_(ve)/D_(ve),0>0.5).The morphological parameters(i.e.,the effective density and the dynamic shape factor)were compared with the measured values to verify the simulated morphology.The simulated mean deviations of morphological parameters were smaller than 8%for the method resolving the particle shape.By applying a realistic shape and refractive index,the mass absorption cross for fully mixed states can be improved by 11%compared with a simplified core–shell model.Based on our understanding of the influence of D_(f)andΔD_(ve)/D_(ve),0 on E_(abs),we propose a two-stage calibration equation to correct the E_(abs)values estimated by the core–shell model,which reduces the simulation error in the Mie calculation by 6%–14%.

关 键 词：Black carbon Mixing states Fractal dimension Dynamic shape factor Absorption enhancement 

分 类 号：TQ424[化学工程]