Direct numerical simulation data obtained from two turbulent, lean hydrogen–air flames propagating in a box are analyzed to explore the influence of combustion-induced thermal expansion on turbulence in unburned gas. For this purpose, Helmholtz–Hodge decomposition is applied to the computed velocity fields. Subsequently, the second-order structure functions conditioned to unburned reactants are sampled from divergence-free solenoidal velocity field or irrotational potential velocity field, yielded by the decomposition. Results show that thermal expansion significantly affects the conditioned potential structure functions not only inside the mean flame brushes but also upstream of them. Upstream of the flames, first, transverse structure functions for transverse potential velocities grow with distance between sampling points more slowly when compared to the counterpart structure functions sampled from the entire or solenoidal velocity field. Second, the former growth rate depends substantially on the distance from the flame-brush leading edge, even at small . Third, potential root mean square (rms) velocities increase with the decrease in distance from the flame-brush leading edge and are comparable with solenoidal rms velocities near the leading edge. Fourth, although the conditioned axial and transverse potential rms velocities are always close to one another, thus implying isotropy of the potential velocity field in unburned reactants, the potential structure functions exhibit a high degree of anisotropy. Fifth, thermal expansion effects are substantial even for the solenoidal structure functions and even upstream of a highly turbulent flame. These findings call for development of advanced models of turbulence in flames, which allow for the discussed thermal expansion effects.
Skip Nav Destination
Article navigation
August 2022
Research Article|
August 03 2022
Conditioned structure functions in turbulent hydrogen/air flames
Special Collection:
Development and Validation of Models for Turbulent Reacting Flows
Vladimir A. Sabelnikov
;
Vladimir A. Sabelnikov
a)
(Conceptualization, Investigation, Writing – review & editing)
1
DMPE ONERA—University of Paris-Saclay
, F-91123 Palaiseau, France
2
Central Aerohydrodynamic Institute (TsAGI)
, 140180 Zhukovsky, Moscow Region, Russian Federation
a)Author to whom correspondence should be addressed: [email protected]
Search for other works by this author on:
Andrei N. Lipatnikov
;
Andrei N. Lipatnikov
(Investigation, Writing – original draft, Writing – review & editing)
3
Department of Mechanics and Maritime Sciences, Chalmers University of Technology
, Gothenburg 41296, Sweden
Search for other works by this author on:
Nikolay V. Nikitin;
Nikolay V. Nikitin
(Methodology)
4
Lomonosov Moscow State University
, Moscow, Russian Federation
Search for other works by this author on:
Francisco E. Hernández-Pérez
;
Francisco E. Hernández-Pérez
(Data curation, Writing – review & editing)
5
Clean Combustion Research Center, King Abdullah University of Science and Technology
, Thuwal 23955-6900, Saudi Arabia
Search for other works by this author on:
Hong G. Im
Hong G. Im
(Data curation, Writing – review & editing)
5
Clean Combustion Research Center, King Abdullah University of Science and Technology
, Thuwal 23955-6900, Saudi Arabia
Search for other works by this author on:
a)Author to whom correspondence should be addressed: [email protected]
Note: This paper is part of the special topic, Development and Validation of Models for Turbulent Reacting Flows.
Physics of Fluids 34, 085103 (2022)
Article history
Received:
April 19 2022
Accepted:
July 09 2022
Citation
Vladimir A. Sabelnikov, Andrei N. Lipatnikov, Nikolay V. Nikitin, Francisco E. Hernández-Pérez, Hong G. Im; Conditioned structure functions in turbulent hydrogen/air flames. Physics of Fluids 1 August 2022; 34 (8): 085103. https://doi.org/10.1063/5.0096509
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
On Oreology, the fracture and flow of “milk's favorite cookie®”
Crystal E. Owens, Max R. Fan (范瑞), et al.
Physics-informed neural networks for solving Reynolds-averaged Navier–Stokes equations
Hamidreza Eivazi, Mojtaba Tahani, et al.
Chinese Academy of Science Journal Ranking System (2015–2023)
Cruz Y. Li (李雨桐), 李雨桐, et al.
Related Content
Characteristics of cylindrical flame acceleration in outward expansion
Physics of Fluids (September 2008)
Effects of Lewis number on vorticity and enstrophy transport in turbulent premixed flames
Physics of Fluids (January 2016)
Scalar transport and the validity of Damköhler’s hypotheses for flame propagation in intense turbulence
Physics of Fluids (August 2017)
Dissipation and dilatation rates in premixed turbulent flames
Physics of Fluids (March 2021)
Effects of Karlovitz number on turbulent kinetic energy transport in turbulent lean premixed methane/air flames
Physics of Fluids (August 2017)