Title: Mobility size and mass of nascent soot particles in a benchmark premixed ethylene flame

Abstract

The burner stabilized stagnation flame technique coupled with micro-orifice probe sampling and mobility sizing has evolved into a useful tool for examining the evolution of the particle size distribution of nascent soot in laminar premixed flames. Several key aspects of this technique are examined through a multi-university collaborative study that involves both experimental measurement and computational modeling. Key issues examined include (a) data reproducibility and facility effects using four burners of different sizes and makers over three different facilities, (b) the mobility diameter and particle mass relationship, and (c) the degree to which the finite orifice flow rate affects the validity of the boundary condition in a pseudo one dimensional stagnation flow flame formulation. The results indicate that different burners across facilities yield nearly identical results after special attention is paid to a range of experimental details, including a proper selection of the sample dilution ratio and quantification of the experimental flame boundary conditions. The mobility size and mass relationship probed by tandem mass and mobility measurement shows that nascent soot with mobility diameter as small as 15 nm can deviate drastically from the spherical shape. Various non-spherical morphology models using a mass density value of 1.5 g/cm³ can reconcilemore » this discrepancy in nascent soot mass. Lastly, two-dimensional axisymmetric simulations of the experimental flame with and without the sample orifice flow reveal several problems of the pseudo one-dimensional stagnation flow flame approximation. The effect of the orifice flow on the flame and soot sampled, although small, is not negligible. Particular suggestions are provided as to how to treat the non-ideality of the experimental setup in experiment and model comparisons.« less

Authors:

Camacho, Joaquin  ^[1];

• Search DOE PAGES for author "Camacho, Joaquin"
• Search DOE PAGES for ORCID "0000-0002-4043-1054"

Liu, Changran  ^[1];

• Search DOE PAGES for author "Liu, Changran"
• Search DOE PAGES for ORCID "0000-0002-0620-785X"

Gu, Chen  ^[2];

• Search DOE PAGES for author "Gu, Chen"
• Search DOE PAGES for ORCID "0000-0002-1809-5744"

Lin, He ^[2]; Huang, Zhen ^[2]; Tang, Quanxi ^[3]; You, Xiaoqing  ^[3];

• Search DOE PAGES for author "You, Xiaoqing"
• Search DOE PAGES for ORCID "0000-0003-4680-4576"

Saggese, Chiara ^[4]; Li, Yang ^[5]; Jung, Heejung ^[5]; Deng, Lei ^[6]; Wlokas, Irenaeus ^[6]; Wang, Hai ^[1]

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+ Show Author Affiliations

1. Stanford Univ., CA (United States)
2. Shanghai Jiao Tong Univ. (China)
3. Tsinghua Univ., Beijing (China)
4. Polytechnic Univ. of Milan (Italy)
5. Univ. of California, Riverside, CA (United States)
6. Univ. of Duisburg-Essen (Germany)

Publication Date:

Fri Aug 07 00:00:00 EDT 2015

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Combustion Energy Frontier Research Center (CEFRC)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Natural Science Foundation of China (NSFC)

OSTI Identifier:

1369837

Alternate Identifier(s):

OSTI ID: 1247774

Grant/Contract Number:  

SC0001198; DESC0001198

Resource Type:

Accepted Manuscript

Journal Name:

Combustion and Flame

Additional Journal Information:

Journal Volume: 162; Journal Issue: 10; Related Information: CEFRC partners with Princeton University (lead); Argonne National Laboratory; University of Connecticut; Cornell University; Massachusetts Institute of Technology; University of Minnesota; Sandia National Laboratories; University of Southern California; Stanford University; University of Wisconsin, Madison; Journal ID: ISSN 0010-2180

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Soot; Mobility sizing; Particle size distribution; Premixed flames