采用有限体积元方法对五腔室圆环挡板振荡流反应器(OFR)的三维浓度场进行了数值模拟研究,考察了腔室中心注入模式下的示踪剂浓度场的分布形态及其在不同振荡条件下的演化情况。研究表明,示踪剂在OFR中运动是由振荡流反应器中主体流动与...采用有限体积元方法对五腔室圆环挡板振荡流反应器(OFR)的三维浓度场进行了数值模拟研究,考察了腔室中心注入模式下的示踪剂浓度场的分布形态及其在不同振荡条件下的演化情况。研究表明,示踪剂在OFR中运动是由振荡流反应器中主体流动与漩涡构成的二次流动对腔室中心区域的交替控制促成的。定义一个腔室中的浓度方差 C 作为判断混合效率的依据,结果表明,C 值是腔室内混合和腔室间混合共同作用的结果。参数表征的混合效率说明振荡雷诺数越大,混合效率越高。统计分析结果表明,基于长程对流混合和短程湍流扩散双模式传递模式的二项指数衰减曲线方程能够较好地描述踪剂浓度分布方差值随时间的变化。展开更多
Photochemical aging of volatile organic compounds(VOCs)in the atmosphere is an important source of secondary organic aerosol(SOA).To evaluate the formation potential of SOA at an urban site in Lyon(France),an outdoor ...Photochemical aging of volatile organic compounds(VOCs)in the atmosphere is an important source of secondary organic aerosol(SOA).To evaluate the formation potential of SOA at an urban site in Lyon(France),an outdoor experiment using a Potential Aerosol Mass(PAM)oxidation flow reactor(OFR)was conducted throughout entire days during JanuaryFebruary 2017.Diurnal variation of SOA formations and their correlation with OH radical exposure(OHexp),ambient pollutants(VOCs and particulate matters,PM),Relative Humidity(RH),and temperature were explored in this study.Ambient urban air was exposed to high concentration of OH radicals with OHexp in range of(0.2-1.2)×10^12 molecule/(cm^3·sec),corresponding to several days to weeks of equivalent atmospheric photochemical aging.The results informed that urban air at Lyon has high potency to contribute to SOA,and these SOA productions were favored from OH radical photochemical oxidation rather than via ozonolysis.Maximum SOA formation(36μg/m^3)was obtained at OHexp of about 7.4×10^11 molecule/(cm^3·sec),equivalent to approximately 5 days of atmospheric oxidation.The correlation between SOA formation and ambient environment conditions(RH&temperature,VOCs and PM)was observed.It was the first time to estimate SOA formation potential from ambient air over a long period in urban environment of Lyon.展开更多
文摘采用有限体积元方法对五腔室圆环挡板振荡流反应器(OFR)的三维浓度场进行了数值模拟研究,考察了腔室中心注入模式下的示踪剂浓度场的分布形态及其在不同振荡条件下的演化情况。研究表明,示踪剂在OFR中运动是由振荡流反应器中主体流动与漩涡构成的二次流动对腔室中心区域的交替控制促成的。定义一个腔室中的浓度方差 C 作为判断混合效率的依据,结果表明,C 值是腔室内混合和腔室间混合共同作用的结果。参数表征的混合效率说明振荡雷诺数越大,混合效率越高。统计分析结果表明,基于长程对流混合和短程湍流扩散双模式传递模式的二项指数衰减曲线方程能够较好地描述踪剂浓度分布方差值随时间的变化。
基金the Institute for Research on Catalysis and the Environment of Lyon(IRCELYON)supported by the"Investissement d’Avenir"PEPS Program Project(ASTRAL)of the University of Lyon and French National center for Scientific Research(French:center national de la recherche scientifique,CNRS)as part of the ANR-11-IDEX-0007 programby the European Research Council under the Horizon 2020 Research and Innovation Program Project of the European Union under Convention N°690958(MARSU)。
文摘Photochemical aging of volatile organic compounds(VOCs)in the atmosphere is an important source of secondary organic aerosol(SOA).To evaluate the formation potential of SOA at an urban site in Lyon(France),an outdoor experiment using a Potential Aerosol Mass(PAM)oxidation flow reactor(OFR)was conducted throughout entire days during JanuaryFebruary 2017.Diurnal variation of SOA formations and their correlation with OH radical exposure(OHexp),ambient pollutants(VOCs and particulate matters,PM),Relative Humidity(RH),and temperature were explored in this study.Ambient urban air was exposed to high concentration of OH radicals with OHexp in range of(0.2-1.2)×10^12 molecule/(cm^3·sec),corresponding to several days to weeks of equivalent atmospheric photochemical aging.The results informed that urban air at Lyon has high potency to contribute to SOA,and these SOA productions were favored from OH radical photochemical oxidation rather than via ozonolysis.Maximum SOA formation(36μg/m^3)was obtained at OHexp of about 7.4×10^11 molecule/(cm^3·sec),equivalent to approximately 5 days of atmospheric oxidation.The correlation between SOA formation and ambient environment conditions(RH&temperature,VOCs and PM)was observed.It was the first time to estimate SOA formation potential from ambient air over a long period in urban environment of Lyon.
