Imperial College London
Alternate

Professor of Thermofluids Mechanical Engineering

Central Faculty, Office of the Provost

Associate Provost (Academic Promotions)
 
 
 
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Contact

 

p.lindstedt

 
 
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Location

 

613City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Tian:2017:10.1080/13647830.2017.1343499,
author = {Tian, L and Lindstedt},
doi = {10.1080/13647830.2017.1343499},
journal = {Combustion Theory and Modelling},
pages = {1114--1147},
title = {The impact of dilatation, scrambling and pressure transport in turbulent premixed flames},
url = {http://dx.doi.org/10.1080/13647830.2017.1343499},
volume = {21},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Premixed turbulent flames feature strong interactions between chemical reactions and turbulence that affect scalar and turbulence statistics. The focus of the present work is on clarifying the impact of pressure dilatation/flamelet scrambling effects with a comprehensive second-moment closure used for evaluation purposes. Model extensions that take into account flamelet orientation and molecular diffusion are derived. Isothermal pressure transport is included with an additional variable density contribution derived for the flamelet regime of combustion. Full closure is assessed by comparisons with Direct Numerical Simulations (DNSs) of statistically ‘steady’ fully developed premixed turbulent planar flames at different expansion ratios. Subsequently, the prediction of lean premixed turbulent methane–air flames featuring fractal grid generated turbulence in an opposed jet geometry is considered. The overall agreement shows that ‘dilatation’ effects contribute to counter-gradient transport and can also increase the turbulent kinetic energy significantly. Levels of anisotropy are broadly consistent with the DNS data and key aspects of opposed jet flames are well predicted. However, it is also shown that complications arise due to interactions between the imposed pressure gradient and combustion and that redistribution is affected along with the scalar flux at the leading edge. The latter is strongly affected by the reaction rate closure and, potentially, by pressure transport. Overall, the derived models offer significant improvements and can readily be applied to the modelling of premixed turbulent flames at practical rates of heat release.
AU  - Tian,L
AU  - Lindstedt
DO  - 10.1080/13647830.2017.1343499
EP  - 1147
PY  - 2017///
SN  - 1741-3559
SP  - 1114
TI  - The impact of dilatation, scrambling and pressure transport in turbulent premixed flames
T2  - Combustion Theory and Modelling
UR  - http://dx.doi.org/10.1080/13647830.2017.1343499
UR  - http://hdl.handle.net/10044/1/48689
VL  - 21
ER  -
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