Development and validation of a multi-angle light scattering method for fast engine soot mass and size measurements
Development and validation of a multi-angle light scattering method for fast engine soot mass and size measurements
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开发和验证用于快速测量发动机烟灰质量和尺寸的多角度光散射方法
DOI：
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发表时间：
2020
影响因子：
5.2
通讯作者：
S. Rogak
中科院分区：
文献类型：
--
作者：
Pooyan Kheirkhah;A. Baldelli;P. Kirchen;S. Rogak
本文介绍了一种用于柴油机非稳态燃烧过程微粒光散射测量的快速排气微粒测量仪。FEN同时测量三个角度的光散射强度，以推断多分散烟灰的质量浓度（Cm）、几何质量平均迁移率直径（dm，g）和几何标准偏差（σm，g）。使用核来确定Cm，dm，g和σm，g，基于用瑞利-德拜-甘斯分形聚集体光散射模型（RDGFA）生成的查找表;该模型结合了初级颗粒尺寸（dp）随聚集体尺寸（da）的变化，以及与烟灰性质相关的九个参数，以及与FEN光学器件相关的一个参数。这些参数由文献和透射电子显微镜（TEM）先验确定。反相Cm和dm，g在重量质量浓度和SMPS迁移率直径的±10%范围内。然而，这在很大程度上取决于用于生成查找表的参数的选择。参数的研究表明，推断的质量是最敏感的煤烟折射率，初级颗粒的大小，和分形前置因子KF的不确定性。考虑到文献中烟尘折射率的范围很宽，以及形态参数对烟尘图像处理的敏感性，质量浓度的不确定度将超过40%。正因为如此，一种新的方法，将初级颗粒的尺寸与聚集体的尺寸相关联，首次被纳入光散射模型，并将不确定性降低到±25- 30%。版权所有© 2020美国气溶胶研究协会
Abstract A Fast Exhaust Nephelometer (FEN) is developed for light scattering measurement of particles produced by unsteady combustion processes, such as in diesel engines. The FEN simultaneously measures the light scattering intensity at three angles to infer the mass concentration (Cm), the geometric mass mean mobility diameter (dm,g), and the geometric standard deviation (σm,g) of polydisperse soot. A kernel is used to determine Cm, dm,g, and σm,g based on lookup tables generated with the Rayleigh-Debye-Gans light scattering model for fractal aggregates (RDGFA); the model incorporates the variation of the primary particle size (dp) with aggregate size (da), and nine parameters related to the soot properties, and one to the FEN optics. These parameters are determined a priori from literature and Transmission Electron Microscopy (TEM). The inverted Cm and dm,g are within ±10% of the gravimetric mass concentration and SMPS mobility diameter. This, however, largely depends on the choice of the parameters used to generate the lookup tables. A parametric study shows the inferred mass is most sensitive to uncertainties in the soot refractive index, the primary particle size, and the fractal pre-factor kf. Considering the wide range of soot refractive indices in the literature and the sensitivity of the morphological parameters to the processing of soot images, the uncertainty in mass concentration would be over 40%. Because of this, a novel approach of relating the size of primary particles to the size of aggregates is incorporated for the first time in the light scattering model, and reduces the uncertainty to ±25–30%. Copyright © 2020 American Association for Aerosol Research
影响因子：
2.1
作者：
Oltmann, H.;Reimann, J.;Will, S.
通讯作者：
Will, S.
DOI：
10.1016/j.jqsrt.2016.06.030
发表时间：
2016-11-01
影响因子：
2.3
作者：
Huber, Franz J. T.;Will, Stefan;Daun, Kyle J.
通讯作者：
Daun, Kyle J.