Numerical and chemical kinetic analysis to evaluate the effect of steam dilution and pressure on combustion of n-dodecane in a swirling flow environment

Subhankar Mohapatra, Subrat Garnayak, Bok Jik Lee, Ayman M. Elbaz, William L. Roberts, Sukanta Kumar Dash, V. Mahendra Reddy

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21 Scopus citations


In the present study, numerical analysis on the effect of steam dilution and high pressure on liquid fuel swirl combustion is carried out using a turbulent non-premixed combustion model. Tangential air injection scheme is adopted in a conical combustor. High recirculation is achieved inside the combustor due to the swirl pattern produced by the tangential air inlets. n-Dodecane, which is a major component of kerosene and Jet-A fuel, is selected as fuel in the present study. The thermal intensity of 5.37 MW/m3 with 21.1 kW thermal input is considered for the computational study. The chamber pressure is varied from 1 to 20 atm, keeping the momentum of inlet airflow constant. Steam added in the oxidizer as a diluent is varied from 0 to 20% by mass. Computational Fluid Dynamics (CFD) analysis using RANS (Reynolds Averaged Navier-Stokes) equations is performed to understand the flow characteristics and study the effect of steam dilution and pressure on NO formation. Realizable k-ε turbulence model is used in the present study to capture the flow behavior due to the swirling motion. Spray characteristics are modelled using the Discrete Phase Model. The chemical representation is realized using scalar conservation concept with β-PDF model. Detailed chemical kinetic analysis with ignition delay characteristics, rate of species production, reaction behavior and sensitivity analysis is carried out. It is observed that the ignition delay decreases rapidly with pressure and very slowly with steam dilution. Effect of pressure and dilution on the OH concentration and olefins are discussed. Peak flame temperature and NO formation decreased with the steam addition. Emission characteristics are presented in the paper.
Original languageEnglish (US)
Pages (from-to)119710
StatePublished - Nov 2020

Bibliographical note

KAUST Repository Item: Exported on 2020-12-16
Acknowledged KAUST grant number(s): CRG
Acknowledgements: The authors (SM, SG, SKD and VMR) would like to acknowledge the funding received for this work from Science and Engineering Research Board (SERB) of India under Core Research Grant (Grant no-CRG/2019/005882). BJL would like to acknowledge the support by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry and Energy (MOTIE) of the Republic of Korea (Grant No. 20181110100290). For the KAUST team (AME and WLR), the research reported in this publication was supported by the Office of Sponsored Research (OSR) at King Abdullah University of Science and Technology (KAUST).


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