Evaluation of a Turbulent Jet Flame Flashback Correlation Applied to Annular Flow Configurations With and Without Swirl

Abstract The adaptation of high hydrogen content fuels for low emissions gas turbines represents a potential opportunity to reduce the carbon footprint of these devices. The high flame speed of hydrogen air mixtures combined with the small quenching distances poses a challenge for using these fuels in situations where significant premixing is desired. Flashback along the walls (i.e., boundary layer flashback) can be exacerbated with high hydrogen content fuels. In the present work, the ability of a flashback correlation previously developed for round jet flames is evaluated for its ability to predict flashback in an annular flow with and without swirl. Flashback data are obtained for various mixtures of hydrogen and methane and hydrogen and carbon monoxide for all the annular flow configurations. Pressures from 3-8 bar are tested with mixture temperatures up to 750 K. Flashback is induced by slowly increasing the equivalence ratio. The results obtained show that the same form of the correlation developed for round jet flames can be used to correlate flashback behavior for the annular flow case with and without swirl despite the presence of the centerbody. Adjustments to some of the constants in the original model were made to obtain the best fit, but in general, the correlation is quite similar to that developed for the round jet flame. A significant difference with the annular flow configurations is the determination of the appropriate gradient at the wall, which in the present case is determined using a cold flow CFD simulation.

Download Full-text

Evaluation of a Turbulent Jet Flame Flashback Correlation Applied to Annular Flow Configurations With and Without Swirl

Volume 4A: Combustion, Fuels, and Emissions ◽

10.1115/gt2020-14703 ◽

2020 ◽

Author(s):

E. Sullivan Lewis ◽

Vincent G. McDonell ◽

Alireza Kalantari ◽

Priyank Saxena

Keyword(s):

Hydrogen Content ◽

Gas Turbines ◽

Annular Flow ◽

Jet Flames ◽

High Hydrogen ◽

Jet Flame ◽

High Hydrogen Content ◽

Round Jet ◽

Significant Difference ◽

Flow Configurations

Abstract The adaptation of high hydrogen content fuels for low emissions gas turbines represents a potential opportunity to reduce the carbon footprint of these devices. The high flame speed of hydrogen air mixtures combined with the small quenching distances poses a challenge for using these fuels in situations where significant premixing is desired. In particular flashback in either the core flow or along the walls (i.e., boundary layer flashback) can be exacerbated with high hydrogen content fuels. In the present work, the ability of a flashback correlation previously developed for round jet flames is evaluated for its ability to predict flashback in an annular flow. As a first step, an annular flow is generated with a centerbody located at the centerline of the original round jet flame. Next, various levels of axial swirl is added to that annular flow. Additional flashback data are obtained for various mixtures of hydrogen and methane and hydrogen and carbon monoxide for all-the annular flow configurations. Pressures from 3–8 bar are tested with mixture temperatures up to 750 K. Flashback is induced by slowly increasing the equivalence ratio. The results obtained show that the same form of the correlation developed for round jet flames can be used to correlate flashback behavior for the annular flow case with and without swirl despite the presence of the centerbody. Adjustments to some of the constants in the original model were made to obtain the best fit, but in general, the correlation is quite similar to that developed for the round jet flame. A significant difference with the annular flow configurations is the determination of the appropriate gradient at the wall, which in the present case is determined using a cold flow CFD simulation.

Download Full-text

Hydrodynamic instability and shear layer effect on the sound emission of a turbulent jet flame

21st AIAA/CEAS Aeroacoustics Conference ◽

10.2514/6.2015-2380 ◽

2015 ◽

Cited By ~ 1

Author(s):

Stephan Schlimpert ◽

Seong Ryong Koh ◽

Antje Feldhusen ◽

Benedikt Roidl ◽

Matthias H. Meinke ◽

...

Keyword(s):

Shear Layer ◽

Hydrodynamic Instability ◽

Turbulent Jet ◽

Sound Emission ◽

Jet Flame ◽

Layer Effect

Download Full-text

Effect of Temperature Conditions on Flame Evolutions of Turbulent Jet Ignition

Energies ◽

10.3390/en14082226 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2226

Author(s):

Jiaying Pan ◽

Yu He ◽

Tao Li ◽

Haiqiao Wei ◽

Lei Wang ◽

...

Keyword(s):

Flame Propagation ◽

Early Stage ◽

Turbulent Jet ◽

Combustion Stability ◽

Effect Of Temperature ◽

Main Chamber ◽

Detailed Chemical Kinetics ◽

Jet Flame ◽

Spherical Flame ◽

Temperature Conditions

Turbulent jet ignition technology can significantly improve lean combustion stability and suppress engine knocking. However, the narrow jet channel between the pre-chamber and the main chamber leads to some difficulties in heat exchange, which significantly affects combustion performance and mechanical component lifetime. To clarify the effect of temperature conditions on combustion evolutions of turbulent jet ignition, direct numerical simulations with detailed chemical kinetics were employed under engine-relevant conditions. The flame propagation in the pre-chamber and the early-stage turbulent jet ignition in the main chamber were investigated. The results show that depending on temperature conditions, two types of flame configuration can be identified in the main chamber, i.e., the normal turbulent jet flame propagation and the spherical flame propagation, and the latter is closely associated with pressure wave disturbance. Under low-temperature conditions, the cold jet stoichiometric mixtures and the vortexes induced by the jet flow determine the early-stage flame development in the main chamber. Under intermediate temperature conditions, pre-flame heat release and leading pressure waves are induced in the jet channel, which can be regarded as a transition of different combustion modes. Whereas under high-temperature conditions, irregular auto-ignition events start to occur, and spherical flame fronts are induced in the main chamber, behaving faster flame propagation.

Download Full-text

Cinema particle imaging velocimetry time history of the propagation velocity of the base of a lifted turbulent jet flame

Proceedings of the Combustion Institute ◽

10.1016/s1540-7489(02)80230-9 ◽

2002 ◽

Vol 29 (2) ◽

pp. 1897-1903 ◽

Cited By ~ 33

Author(s):

Ansis Upatnieks ◽

James F. Driscoll ◽

Steven L. Ceccio

Keyword(s):

Propagation Velocity ◽

Time History ◽

Turbulent Jet ◽

Particle Imaging Velocimetry ◽

Jet Flame ◽

History Of ◽

Particle Imaging

Download Full-text

Simulation of Methanol-Air Two-Phase Flames Using Various Turbulent Combustion Models

Volume 2: Combustion, Fuels and Emissions ◽

10.1115/gt2009-59344 ◽

2009 ◽

Author(s):

F. Wang ◽

Y. Huang ◽

Y. Z. Wu

Keyword(s):

Experimental Data ◽

Turbulent Combustion ◽

Turbulent Jet ◽

Combustion Model ◽

Air Flow Rate ◽

Two Phase ◽

Jet Flame ◽

Combustion Simulation ◽

Turbulent Combustion Model ◽

Turbulent Models

Though fossil fuel is running out, liquid fuels nowadays still provide the most energy used by industrial furnaces, automotive and aero engines. How to predict a two-phase turbulent combustion flame is still a big problem to designers. Generally, the liquid fuel is sprayed and mixed with oxygen, and the flame characteristics depends on the fuel atomization, the fuel droplet spatial distribution, and its interaction with the turbulent oxidizer flow field: turbulent heat, mass and momentum transfer, complicated chemical kinetics, and turbulent-chemistry interaction. Turbulent combustion model is a key point for the two phase combustion simulation. For its short time consuming, Reynolds Averaged Navier Stokes (RANS) method nowadays still is the major tool for gas turbine chamber (GTC) designers, but there is not a universal method in RANS GTC spray combustion simulation at present especially for the two-phase turbulent combustion. The Eddy-Break-Up turbulent combustion model (EBU), Eddy Dissipation Concept turbulent combustion model (EDC), steady Laminar Flame-let turbulent combustion Model (LFM) and the Composition PDF transport turbulent combustion model (CPDF) are all widely used models. In this paper, these four turbulent models are used to simulate a methane-air turbulent jet flame measured by Sandia Lab first, then three methanol-air two-phase turbulent flames, in order to know the ability of these turbulent models. In the gas turbulent jet flame simulation, the result of LFM model and CPDF model are in better agreement with the experimental data than those of the EBU and the EDC models’ results. The reason is that the EBU model and EDC model are overestimated the effect of turbulent. In the three different cases of the two phase combustion simulation, CPDF is the best. The prediction ability of the other three models is different in different cases. The EDC predictions are closer to the experimental data when the air flow rate value is lower, whereas the LFM predictions are better when the air flow rate value is higher.

Download Full-text