Article
Thermodynamics
Shiming Zhang, Zhen Lu, Yue Yang
Summary: In this study, the boundary-layer flashback (BLF) of CH4/H2/air swirling flames at high pressures is modeled using large-eddy simulations with the flame-surface-density method (LES-FSD). A local displacement speed model is employed to account for the thermo-diffusive effects, flame surface curvature, and heat loss. The study successfully captures the propagation characteristics during the BLF of swirling flames and develops a simple model to predict the flashback limits.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Andreas Goldmann, Friedrich Dinkelacker
Summary: The study investigates the combustion properties of hydrogen/ammonia blends, revealing that as the ammonia content increases, the mean flow velocities during flame flashback exponentially decrease. A new experimental setup and theoretical modeling are introduced to predict the flashback limits with high accuracy.
COMBUSTION AND FLAME
(2021)
Article
Energy & Fuels
Chunyu Liu, Haojie Yang, Can Ruan, Liang Yu, Jiaqi Nan, Jingxuan Li, Xingcai Lu
Summary: Ammonia (NH3) has emerged as a promising carbon-free energy carrier and its further development and application in the gas turbine industry can reduce carbon dioxide (CO2) emissions and contribute to carbon neutrality. This study experimentally investigated the instability characteristics of a lean premixed gas turbine combustor using NH3 blended with methane (CH4). The results showed that the concentration of NH3 is critical in determining the instability characteristics, with a mode transition occurring when the NH3 proportion is less than 50%. However, when the NH3 content is higher than 50%, the instabilities are suppressed, indicating that a certain amount of NH3 can enhance the stability of CH4 flames.
Article
Thermodynamics
Andreas Goldmann, Friedrich Dinkelacker
Summary: Hydrogen and ammonia are being considered as carbon-free energy carriers for gas turbines and combustion systems. The study investigates boundary layer flashback for various mixtures, finding that ammonia content in the fuel mixture has a stronger impact on flashback propensity than nitrogen content. Oxygen enrichment and increased unburned mixture temperature can double the mean flow velocity at flashback onset. New substitute mixtures with methane-like flashback propensity were found by increasing ammonia content to reduce the laminar burning velocity.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Syed Mashruk, Xuren Zhu, William L. Roberts, Thibault F. Guiberti, Agustin Valera-Medina
Summary: This study investigates the chemiluminescence characteristics of premixed ammonia-methane-air swirling flames. The effects of equivalence ratio, ammonia fraction in the fuel blend, and Reynolds number on the emitted light were examined. Excited radicals contributing to chemiluminescence in the UV and visible ranges were identified, and various ratios of chemiluminescence intensities were studied to remove the effects of time-varying flame surface area.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
F. H. Vance, L. P. H. de Goey, J. A. van Oijen
Summary: Hydrogen flames have a higher tendency to flashback compared to methane flames, which can lead to strong thermal stresses in burners and hinder their performance. Studies have shown that traditional flashback correlation methods are not effective in accounting for stretch induced preferential diffusion effects, and a new Karlovitz number definition has been introduced to better understand and predict flashback limits.
COMBUSTION AND FLAME
(2022)
Article
Chemistry, Physical
Tahsin Berk Kiymaz, Emre Boncu, Dilay Guleryuz, Mehmet Karaca, Baris Yilmaz, Christophe Allouis, Iskender Gokalp
Summary: This study used OpenFOAM to compute the flashback propensity of laminar premixed methane-hydrogen-air flames and found that the tendency for flashback increases with increasing wall temperature and hydrogen addition rate.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Wenjun Lin, Wang Han, Jinhua Wang, Runze Mao, Weijie Zhang, Xiao Cai, Zuohua Huang
Summary: The role of low-temperature chemistry/ignition (LTC/LTI) was studied in aero engine-like combustors with confined bluff-body and swirling flows. Experimental investigations were conducted on CH4/DME/air mixtures with varying DME volume fraction (αDME) to consider LTI. It was found that adding DME to lean CH4/air mixtures can introduce low-temperature flames (LTF) in the outer recirculation zone (ORZ) under certain conditions. The flame regimes were classified based on DME enrichment, and the possibility of using LTI to extend the stability margin of lean swirling flames was demonstrated.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Energy & Fuels
Liubin Hu, Hao Zhou
Summary: This study examines the influence of renewable energy biogas addition on methane self-excited thermoacoustic oscillation and pollutant NOx emission. It also explores the effects of swirl intensity and methane enrichment on biogas combustion. The results show that biogas addition effectively suppresses methane premixed self-excited oscillation swirling flames and promotes high-frequency self-excited oscillation and swirl stable combustion. Overall flame temperature and NOx emissions are reduced, indicating that biogas introduction effectively restrains thermoacoustic oscillation and limits NOx emissions. However, enriching biogas with more methane leads to better biogas/methane flame dynamics but higher NOx generation.
JOURNAL OF THE ENERGY INSTITUTE
(2023)
Article
Thermodynamics
F. H. Vance, Y. Shoshin, L. P. H. de Goey, J. A. van Oijen
Summary: By varying the radius of flame holders and mixture velocity, different mechanisms of flame stabilization can be observed under different conditions. Flame curvature plays a significant role in flame stretch, and the presence of RZ alters the stabilization mechanism of the flame.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Chemistry, Physical
Filippo Fruzza, Rachele Lamioni, Leonardo Tognotti, Chiara Galletti
Summary: This study investigates the flashback of different H2/CH4 mixtures and proposes a numerical model to predict the critical flashback velocity for laminar premixed flames.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Zongming Yu, Yuhua Ai, Yue Wang, Chuanzhi Luo
Summary: The study investigated the thermoacoustic instability of a laminar lean premixed flame in gas turbine combustors through theoretical analysis and numerical simulation, focusing on the autoignition and propagation mechanism of the flame. Results showed that the three-step mechanism could effectively describe the high-temperature chemistry involved in autoignition and flame propagation.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
F. H. Vance, Y. Shoshin, L. P. H. de Goey, J. A. van Oijen
Summary: This study focuses on the mechanisms governing flame stabilization without a vortex, redefines flame anchoring locations, and evaluates the impact of flame holder size on flame speed. New insights into flame blow-off, flashback, and vortex emergence are obtained as a result of this investigation.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Hyebin Kang, Changjin Yoon, Kyu Tae Kim
Summary: Understanding the thermoacoustic properties of lean-premixed hydrogen flames is crucial for the development of hydrogen-capable gas turbines. This study investigates the dynamic response of these flames to velocity perturbations using direct measurements and numerical simulations. The results show the differences between OH intensity distribution and heat release rate contours, indicating uncertainties in surrogate-dependent flame transfer function evaluations. A reduced-order network modeling framework combined with direct measurement is used to test the accuracy of self-sustained pressure fluctuation predictions, and it is found that LES-based transfer functions can predict the system's stability more accurately.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Bing-xuan Lin, Yun Wu, Ming-xing Xu, Zhi-gang Chen
Summary: The ignition process of kerosene spray in an aero-engine combustor is complex and sensitive to injection pressure and air velocity, with the ignition location affecting flame integrity. Successful ignition sparks lead to flame kernels moving towards the nozzle, while failed ignition events result in rapid extinguishment of the flame kernel.
Article
Thermodynamics
Hidemasa Kosaka, Florian Zentgraf, Arne Scholtissek, Christian Hasse, Andreas Dreizler
FLOW TURBULENCE AND COMBUSTION
(2020)
Article
Thermodynamics
Salvador Navarro-Martinez, Giovanni Tretola, Mohammad Reza Yosri, Robert L. Gordon, Konstantina Vogiatzaki
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2020)
Correction
Mechanics
H. Hill, C. -P. Ding, E. Baum, B. Boehm, A. Dreizler, B. Peterson
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2020)
Article
Engineering, Electrical & Electronic
Javad Jazaeri, Tansu Alpcan, Robert L. Gordon
IEEE TRANSACTIONS ON SMART GRID
(2020)
Article
Thermodynamics
R. Ciardiello, A. W. Skiba, R. L. Gordon, E. Mastorakos
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2020)
Article
Engineering, Mechanical
Tao Li, Bo Zhou, Jonathan H. Frank, Andreas Dreizler, Benjamin Boehm
EXPERIMENTS IN FLUIDS
(2020)
Article
Thermodynamics
Marius Schmidt, Carl-Philipp Ding, Brian Peterson, Andreas Dreizler, Benjamin Boehm
Summary: This study investigates near-wall processes in internal combustion engines by measuring flame distributions and flow fields. The interaction between flame and flow under different operating conditions leads to variations in burnt gas positions within the field-of-view. The presence of flame significantly affects the velocity boundary layer profiles.
FLOW TURBULENCE AND COMBUSTION
(2021)
Article
Thermodynamics
M. Steinhausen, Y. Luo, S. Popp, C. Strassacker, T. Zirwes, H. Kosaka, F. Zentgraf, U. Maas, A. Sadiki, A. Dreizler, C. Hasse
Summary: This study analyzes the local heat-release rate and thermo-chemical state of laminar methane and dimethyl ether flames in a side-wall quenching configuration, comparing detailed chemistry simulations and reduced chemistry manifolds with experimental data. The results show a high prediction quality of the chemistry manifolds and extend these findings to more complex oxygenated fuels. Additionally, this work presents the first comparison of the QFM and the REDIM in a side-wall quenching burner.
FLOW TURBULENCE AND COMBUSTION
(2021)
Article
Thermodynamics
J. Trabold, S. Hartl, S. Walther, A. Johchi, A. Dreizler, D. Geyer
Summary: The study focuses on the combustion fundamentals of complex fuels using a novel Temperature Controlled Jet Burner system, comparing different flame characteristics and investigating the influence of Lewis-number on flame wrinkling. The research emphasizes the need for more detailed experimental analyses of the full thermochemical state of laminar and turbulent flames fueled with complex fuels.
FLOW TURBULENCE AND COMBUSTION
(2021)
Article
Energy & Fuels
Lukas G. Becker, Stefan Pielsticker, Benjamin Boehm, Reinhold Kneer, Andreas Dreizler
Article
Energy & Fuels
H. Nicolai, G. Kuenne, R. Knappstein, H. Schneider, L. G. Becker, C. Hasse, F. di Mare, A. Dreizler, J. Janicka
Article
Thermodynamics
Jen Zen Ho, Mohsen Talei, Robert L. Gordon, Michael J. Brear
Summary: Investigation into sound generation by planar flame annihilation for methane/hydrogen/air premixed flames was conducted using 1D fully-resolved simulations. Different stages of annihilation were observed for varying hydrogen content in the fuel mixture, with the time derivative of the heat release rate confirmed as the dominant source of sound.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Chemistry, Multidisciplinary
Anna Schmidt, Matthias Bonarens, Ilia Roisman, Kaushal Nishad, Amsini Sadiki, Andreas Dreizler, Jeanette Hussong, Steven Wagner
Summary: This work presents an experimental investigation of AdBlue film formation in a generic SCR exhaust gas test bench, measuring liquid film thickness and analyzing correlations with wall temperature. The results show reproducible film thicknesses with a standard deviation of 3.4%. Numerical analysis reveals dynamics of AdBlue droplet impingement and film formation.
APPLIED SCIENCES-BASEL
(2021)
Article
Energy & Fuels
Shreshtha Kumar Gupta, Santanu Pramanik, Robert Lindsay Gordon, R. V. Ravikrishna, Vaibhav Kumar Arghode
Summary: The effect of fuel-to-air jet momentum flux ratios on a Reverse-Cross-Flow combustor was investigated using both experimental and numerical methods. The results showed that an increase in the fuel-to-air jet momentum flux ratio led to an increase in CO emissions and a decrease in NOx emissions.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Article
Physics, Fluids & Plasmas
Manuel Vogel, Michael Bachfischer, Jan Kaufmann, Thomas Sattelmayer
Summary: A measurement technique for determining the global and local equivalence ratios in swirl-stabilized lean premixed combustion of natural gas and kerosene is presented. The technique involves using spectrally resolved chemiluminescence studies and bandpass-filtered image acquisition to correlate chemiluminescence signals with the equivalence ratio. The technique allows for high temporal resolution determination of the local equivalence ratio, which can be used to quantify equivalence ratio oscillations during unstable combustion.
