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Title: Velocity and Reactive Scalar Dissipation Spectra in Turbulent Premixed Flames

Dissipation spectra of velocity and reactive scalars—temperature and fuel mass fraction—in turbulent premixed flames are studied using direct numerical simulation data of a temporally evolving lean hydrogen-air premixed planar jet (PTJ) flame and a statistically stationary planar lean methane-air (SP) flame. Furthermore, the equivalence ratio in both cases was 0.7, the pressure 1 atm while the unburned temperature was 700 K for the hydrogen-air PTJ case and 300 K for methane-air SP case, that resulted in data sets with a density ratio of 3 and 5, respectively. The turbulent Reynolds numbers for the cases ranged from 200 to 428.4, the Damköhler number from 3.1 to 29.1, and the Karlovitz number from 0.1 to 4.5. The dissipation spectra collapse when normalized by the respective Favre-averaged dissipation rates. But, the normalized dissipation spectra in all the cases deviate noticeably from those predicted by classical scaling laws for constant-density turbulent flows and bear a clear influence of the chemical reactions on the dissipative range of the energy cascade.
Authors:
 [1] ;  [2] ;  [1] ; ORCiD logo [3]
  1. Sandia National Lab. (SNL-CA), Livermore, CA (United States). Combustion Research Facility
  2. Univ. of Connecticut, Storrs, CT (United States). Dept. of Mechanical Engineering
  3. Univ. of Cambridge (United Kingdom). Dept. of Engineering
Publication Date:
Report Number(s):
SAND2017-7035J
Journal ID: ISSN 0010-2202; 655014
Grant/Contract Number:
AC04-94AL85000; AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Combustion Science and Technology
Additional Journal Information:
Journal Volume: 188; Journal Issue: 9; Journal ID: ISSN 0010-2202
Publisher:
Taylor & Francis
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Direct numerical simulation; Dissipation spectra; Spectral cascade; Turbulent premixed flames
OSTI Identifier:
1372305