Skip to main content Accessibility help
×
Home
Hostname: page-component-684899dbb8-t7hbd Total loading time: 0.289 Render date: 2022-05-21T10:37:03.101Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true }

Two-stage autoignition and edge flames in a high pressure turbulent jet

Published online by Cambridge University Press:  04 July 2017

Alex Krisman*
Affiliation:
School of Mechanical and Manufacturing Engineering, University of New South Wales, Kensington, NSW 2052, Australia Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94550, USA
Evatt R. Hawkes
Affiliation:
School of Mechanical and Manufacturing Engineering, University of New South Wales, Kensington, NSW 2052, Australia School of Photovoltaics and Renewable Energy Engineering, University of New South Wales, Kensington, NSW 2052, Australia
Jacqueline H. Chen
Affiliation:
Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94550, USA
*
Email address for correspondence: ankrism@sandia.gov

Abstract

A three-dimensional direct numerical simulation is conducted for a temporally evolving planar jet of n-heptane at a pressure of 40 atmospheres and in a coflow of air at 1100 K. At these conditions, n-heptane exhibits a two-stage ignition due to low- and high-temperature chemistry, which is reproduced by the global chemical model used in this study. The results show that ignition occurs in several overlapping stages and multiple modes of combustion are present. Low-temperature chemistry precedes the formation of multiple spatially localised high-temperature chemistry autoignition events, referred to as ‘kernels’. These kernels form within the shear layer and core of the jet at compositions with short homogeneous ignition delay times and in locations experiencing low scalar dissipation rates. An analysis of the kernel histories shows that the ignition delay time is correlated with the mixing rate history and that the ignition kernels tend to form in vortically dominated regions of the domain, as corroborated by an analysis of the topology of the velocity gradient tensor. Once ignited, the kernels grow rapidly and establish edge flames where they envelop the stoichiometric isosurface. A combination of kernel formation (autoignition) and the growth of existing burning surface (via edge-flame propagation) contributes to the overall ignition process. An analysis of propagation speeds evaluated on the burning surface suggests that although the edge-flame speed is promoted by the autoignitive conditions due to an increase in the local laminar flame speed, edge-flame propagation of existing burning surfaces (triggered initially by isolated autoignition kernels) is the dominant ignition mode in the present configuration.

Type
Papers
Copyright
© 2017 Cambridge University Press 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Al-Noman, S. M., Choi, S. K. & Chung, S. H. 2015 Autoignition characteristics of laminar lifted jet flames of pre-vaporized iso-octane in heated coflow air. Fuel 162, 171178.CrossRefGoogle Scholar
Arndt, C. M., Papageorge, M. J., Fuest, F., Sutton, J. A., Meier, W. & Aigner, M. 2016 The role of temperature, mixture fraction, and scalar dissipation rate on transient methane injection and auto-ignition in a jet in hot coflow burner. Combust. Flame 167, 6071.CrossRefGoogle Scholar
Borghesi, G., Mastorakos, E. & Cant, R. S. 2013 Complex chemistry DNS of n-heptane spray autoignition at high pressure and intermediate temperature conditions. Combust. Flame 160 (7), 12541275.CrossRefGoogle Scholar
Buckmaster, J. 2002 Edge-flames. Prog. Energy Combust. Sci. 28 (5), 435475.CrossRefGoogle Scholar
Cao, S. & Echekki, T. 2007 Autoignition in nonhomogeneous mixtures: conditional statistics and implications for modeling. Combust. Flame 151, 120141.CrossRefGoogle Scholar
Chakraborty, N. & Mastorakos, E. 2008 Direct numerical simulations of localised forced ignition in turbulent mixing layers: the effects of mixture fraction and its gradient. Flow Turbul. Combust. 80 (2), 155186.CrossRefGoogle Scholar
Chatakonda, O., Hawkes, E. R., Aspden, A. J., Kerstein, A. R., Kolla, H. & Chen, J. H. 2013 On the fractal characteristics of low Damköhler number flames. Combust. Flame 160 (11), 24222433.CrossRefGoogle Scholar
Chen, J. H., Choudhary, A., de Supinski, B., DeVries, M., Hawkes, E. R., Klasky, S., Liao, W. K., Ma, K. L., Mellor-Crummey, J., Podhorszki, N. et al. 2009 Terascale direct numerical simulations of turbulent combustion using S3D. Comput. Sci. Disc. 2 (1), 015001.CrossRefGoogle Scholar
Choi, S. K. & Chung, S. H. 2013 Autoignited and non-autoignited lifted flames of pre-vaporized n-heptane in coflow jets at elevated temperatures. Combust. Flame 160 (9), 17171724.CrossRefGoogle Scholar
Chong, M. S., Perry, A. E. & Cantwell, B. J. 1990 A general classification of three dimensional flow fields. Phys. Fluids A 2 (5), 765777.CrossRefGoogle Scholar
Cifuentes, L., Dopazo, C., M., J. & Jimenez, C. 2014 Local flow topologies and scalar structures in a turbulent premixed flame. Phys. Fluids 26 (6), 065108.CrossRefGoogle Scholar
Dahms, R. N., Paczko, G. A., Skeen, S. A. & Pickett, L. M. 2017 Understanding the ignition mechanism of high-pressure spray flames. Proc. Combust. Inst. 36 (2), 26152623.CrossRefGoogle Scholar
Dec, J. E.1997 A conceptual model of DI diesel combustion based on laser-sheet imaging. SAE Paper 1997-97-0873.Google Scholar
Deng, S., Zhao, P., Mueller, M. E. & Law, C. K. 2015a Autoignition-affected stabilization of laminar nonpremixed DME/air coflow flames. Combust. Flame 162 (9), 34373445.CrossRefGoogle Scholar
Deng, S., Zhao, P., Mueller, M. E. & Law, C. K. 2015b Stabilization of laminar nonpremixed DME/air coflow flames at elevated temperatures and pressures. Combust. Flame 162 (12), 44714478.CrossRefGoogle Scholar
Domingo, P. & Vervisch, L. 1996 Triple flames and partially premixed combustion in autoignition of non-premixed turbulent mixtures. Proc. Combust. Inst. 26 (1), 233240.CrossRefGoogle Scholar
Echekki, T. & Chen, J. H. 1998 Structure and propagation of methanol-air triple flames. Combust. Flame 114, 231245.CrossRefGoogle Scholar
Echekki, T. & Chen, J. H. 2002 High-temperature combustion in autoigniting non-homogeneous hydrogen/air mixtures. Proc. Combust. Inst. 29 (2), 20612068.CrossRefGoogle Scholar
Fieweger, K., Blumenthal, R. & Adomeit, G. 1997 Self-ignition of s.i. engine model fuels: a shock tube investigation at high pressure. Combust. Flame 109 (4), 599619.CrossRefGoogle Scholar
Fleck, J. M., Griebel, P., Steinberg, A. M., Arndt, C. M. & Aigner, M. 2013a Auto-ignition and flame stabilization of hydrogen/natural gas/nitrogen jets in a vitiated cross-flow at elevated pressure. Int. J. Hydr. Energ. 38 (36), 1644116452.CrossRefGoogle Scholar
Fleck, J. M., Griebel, P., Steinberg, A. M., Arndt, C. M., Naumann, C. & Aigner, M. 2013b Autoignition of hydrogen/nitrogen jets in vitiated air crossflows at different pressures. Proc. Combust. Inst. 34 (2), 31853192.CrossRefGoogle Scholar
Fu, X. & Aggarwal, S. K. 2015 Two-stage ignition and NTC phenomenon in diesel engines. Fuel 144, 188196.CrossRefGoogle Scholar
Gong, C., Jangi, M. & Bai, X. S. 2014 Large eddy simulation of n-dodecane spray combustion in a high pressure combustion vessel. App. Energ 136, 373381.CrossRefGoogle Scholar
Grout, R. W., Gruber, A., Yoo, C. S. & Chen, J. H. 2011 Direct numerical simulation of flame stabilization downstream of a transverse fuel jet in cross-flow. Proc. Combust. Inst. 33 (1), 16291637.CrossRefGoogle Scholar
Hawkes, E. R., Sankaran, R. & Chen, J. H. 2008 Extinction and reignition in direct numerical simulations of CO/H2 temporal plane jet flames. In Proceedings of the Australian Combustion Symposium, Newcastle, Australia, 2008, pp. 12711274. Combustion Institute, Australia and New Zealand Section.Google Scholar
Hawkes, E. R., Sankaran, R., Sutherland, J. C. & Chen, J. H. 2007 Scalar mixing in direct numerical simulations of temporally evolving plane jet flames with skeletal CO/H2 kinetics. Proc. Combust. Inst. 31 (1), 16331640.CrossRefGoogle Scholar
Hinze, J. O. 1975 Turbulence. McGraw-Hill.Google Scholar
Idicheria, C. A. & Pickett, L. M.2006 Formaldehyde visualization near lift-off location in a diesel jet. SAE Paper 2006-01-3434.Google Scholar
Im, H. G. & Chen, J. H. 1999 Structure and propagation of triple flames in partially premixed hydrogen-air mixtures. Combust. Flame 119 (4), 436454.CrossRefGoogle Scholar
Im, H. G., Chen, J. H. & Law, C. K. 1998 Ignition of hydrogen-air mixing layer in turbulent flows. Symp. (Int.) Combust. 27 (1), 10471056.CrossRefGoogle Scholar
Karami, S., Hawkes, E. R., Talei, M. & Chen, J. H. 2015 Mechanisms of flame stabilisation at low lifted height in a turbulent lifted slot-jet flame. J. Fluid Mech. 777, 633689.CrossRefGoogle Scholar
Karami, S., Hawkes, E. R., Talei, M. & Chen, J. H. 2016 Edge flame structure in a turbulent lifted flame: a direct numerical simulation study. Combust. Flame 169, 110128.CrossRefGoogle Scholar
Karami, S., Talei, M., Hawkes, E. R. & Chen, J. H. 2017 Local extinction and reignition mechanism in a turbulent lifted flame: a direct numerical simulation study. Proc. Combust. Inst. 36 (2), 16851692.CrossRefGoogle Scholar
Kennedy, C. A. & Carpenter, M. H. 1994 Several new numerical methods for compressible shear-layer simulations. Appl. Numer. Maths 14 (4), 397433.CrossRefGoogle Scholar
Kerkemeier, S. G., Markides, C. N., Frouzakis, C. E. & Boulouchos, K. 2013 Direct numerical simulation of the autoignition of a hydrogen plume in a turbulent coflow of hot air. J. Fluid Mech. 720, 424456.CrossRefGoogle Scholar
Krisman, A., Hawkes, E. R., Talei, M., Bhagatwala, A. & Chen, J. H. 2015 Polybrachial structures in dimethyl ether edge-flames at negative temperature coefficient conditions. Proc. Combust. Inst. 35 (1), 9991006.CrossRefGoogle Scholar
Krisman, A., Hawkes, E. R., Talei, M., Bhagatwala, A. & Chen, J. H. 2016 Characterisation of two-stage ignition in diesel engine-relevant thermochemical conditions using direct numerical simulation. Combust. Flame 172, 326341.CrossRefGoogle Scholar
Krisman, A., Hawkes, E. R., Talei, M., Bhagatwala, A. & Chen, J. H. 2017 A direct numerical simulation of cool-flame affected autoignition in diesel engine-relevant conditions. Proc. Combust. Inst. 36 (3), 35673575.CrossRefGoogle Scholar
Lignell, D. O., Chen, J. H. & Smith, P. J. 2008 Three-dimensional direct numerical simulation of soot formation and transport in a temporally evolving nonpremixed ethylene jet flame. Combust. Flame 155 (12), 316333.CrossRefGoogle Scholar
Liu, S., Hewson, J. C., Chen, J. H. & Pitsch, H. 2004 Effects of strain rate on high-pressure nonpremixed n-heptane autoignition in counterflow. Combust. Flame 137 (3), 320339.CrossRefGoogle Scholar
Lu, T. F., Yoo, C. S., Chen, J. H. & Law, C. K. 2010 Three-dimensional direct numerical simulation of a turbulent lifted hydrogen jet flame in heated coflow: a chemical explosive mode analysis. J. Fluid Mech. 652, 4564.CrossRefGoogle Scholar
Lyra, S., Wilde, B., Kolla, H., Seitzman, J. M., Lieuwen, T. C. & Chen, J. H. 2015 Structure of hydrogen-rich transverse jets in a vitiated turbulent flow. Combust. Flame 162 (4), 12341248.CrossRefGoogle Scholar
Maes, N., Meijer, M., Dam, N., Somers, B., Toda, H. B., Bruneaux, G., Skeen, S. A., Pickett, L. M. & Manin, J. 2016 Characterization of spray a flame structure for parametric variations in ecn constant-volume vessels using chemiluminescence and laser-induced fluorescence. Combust. Flame 174, 138151.CrossRefGoogle Scholar
Markides, C. N., De Paola, G. & Mastorakos, E. 2007 Measurements and simulations of mixing and autoignition of an n-heptane plume in a turbulent flow of heated air. Exp. Therm. Fluid Sci. 31 (5), 393401.CrossRefGoogle Scholar
Markides, C. N. & Mastorakos, E. 2005 An experimental study of hydrogen autoignition in a turbulent co-flow of heated air. Proc. Combust. Inst. 30 (1), 883891.CrossRefGoogle Scholar
Markides, C. N. & Mastorakos, E. 2011 Experimental investigation of the effects of turbulence and mixing on autoignition chemistry. Flow Turbul. Combust. 86 (3–4), 585608.CrossRefGoogle Scholar
Mastorakos, E. 2009 Ignition of turbulent non-premixed flames. Prog. Energy Combust. Sci. 35 (1), 5797.CrossRefGoogle Scholar
Mastorakos, E., Baritaud, T. A. & Poinsot, T. J. 1997 Numerical simulations of autoignition in turbulent mixing flows. Combust. Flame 109, 198223.CrossRefGoogle Scholar
Micka, D. J. & Driscoll, J. F. 2012 Stratified jet flames in a heated (1390 k) air cross-flow with autoignition. Combust. Flame 159 (3), 12051214.CrossRefGoogle Scholar
Minamoto, Y. & Chen, J. H. 2016 DNS of a turbulent lifted DME jet flame. Combust. Flame 169, 3850.CrossRefGoogle Scholar
Mukhopadhyay, S. & Abraham, J. 2012a Influence of heat release and turbulence on scalar dissipation rate in autoigniting n-heptane/air mixtures. Combust. Flame 159 (9), 28832895.CrossRefGoogle Scholar
Mukhopadhyay, S. & Abraham, J. 2012b Influence of turbulence on autoignition in stratified mixtures under compression ignition engine conditions. Proc. Inst. Mech. Engrs 227 (5), 748760.CrossRefGoogle Scholar
Müller, C. M., Breitbach, H. & Peters, N. 1994 Partially premixed turbulent flame propagation in jet flames. Proc. Combust. Inst. 25 (1), 10991106.CrossRefGoogle Scholar
Müller, C. M. & Peters, N. 1992 Global kinetics for n-heptane ignition at high pressures. Proc. Combust. Inst. 20, 777784.CrossRefGoogle Scholar
Musculus, M. P. B., Miles, P. C. & Pickett, L. M. 2013 Conceptual models for partially premixed low-temperature diesel combustion. Prog. Energy Combust. Sci. 39, 246283.CrossRefGoogle Scholar
Pantano, C. 2004 Direct simulation of non-premixed flame extinction in a methane-air jet with reduced chemistry. J. Fluid Mech. 514, 231270.CrossRefGoogle Scholar
Papageorge, M. J., Arndt, C., Fuest, F., Meier, W. & Sutton, J. A. 2014 High-speed mixture fraction and temperature imaging of pulsed, turbulent fuel jets auto-igniting in high-temperature, vitiated co-flows. Exp. Fluids 55 (7), 1763.CrossRefGoogle Scholar
Pei, Y., Hawkes, E. R., Bolla, M., Kook, S., Goldin, G. M., Yang, Y., Pope, S. B. & Som, S. 2016 An analysis of the structure of an n-dodecane spray flame using TPDF modelling. Combust. Flame 168, 420435.CrossRefGoogle Scholar
Peters, N. 2001 Turbulent Combustion, vol. 12. Cambridge University Press.Google Scholar
Pickett, L. M., Kook, S. & Williams, T. C.2009 Visualization of diesel spray penetration, cool-flame, ignition, high- temperature combustion, and soot formation using high-speed imaging. SAE paper 2009-01-0658.Google Scholar
Pickett, L. M., Siebers, D. L. & Idicheria, C. A.2005 Relationship between ignition processes and the lift-off length of diesel fuel jets. SAE Paper 2005-01-3843.Google Scholar
Poinsot, T. J. 1992 Boundary conditions for direct simulations of compressible viscous flows. J. Comput. Phys. 99 (2), 352.CrossRefGoogle Scholar
Pope, S. B. 2000 Turbulent Flows. Cambridge University Press.CrossRefGoogle Scholar
Ruetsch, G. R., Vervisch, L. & Liñán, A. 1995 Effects of heat release on triple flames. Phys. Fluids 7 (6), 14471454.CrossRefGoogle Scholar
Sankaran, R., Hawkes, E. R., Chen, J. H., Lu, T. & Law, C. K. 2007 Structure of a spatially developing turbulent lean methane–air bunsen flame. Proc. Combust. Inst. 31 (1), 12911298.CrossRefGoogle Scholar
Sankaran, R., Hawkes, E. R., Yoo, C. S. & Chen, J. H. 2015 Response of flame thickness and propagation speed under intense turbulence in spatially developing lean premixed methane–air jet flames. Combust. Flame 162 (9), 32943306.CrossRefGoogle Scholar
Siebers, D. L. & Higgins, B.2001 Flame lift-off on direct-injection diesel sprays under quiescent conditions. SAE Paper 2001-01-0530.Google Scholar
Siebers, D. L., Higgins, B. & Pickett, L.2002 Flame lift-off on direct-injection diesel fuel jets: oxygen concentration effects. SAE Paper 2002-01-0890.Google Scholar
Sreedhara, S. & Lakshmisha, K. N. 2000 Direct numerical simulation of autoignition in a non-premixed, turbulent medium. Proc. Combust. Inst. 28 (1), 2533.CrossRefGoogle Scholar
Sreedhara, S. & Lakshmisha, K. N. 2002 Autoignition in a non-premixed medium: DNS studies on the effects of three-dimensional turbulence. Proc. Combust. Inst. 29 (2), 20512059.CrossRefGoogle Scholar
Sripakagorn, P., Mitarai, S., Kosály, G. & Pitsch, H. 2004 Extinction and reignition in a diffusion flame: a direct numerical simulation study. J. Fluid Mech. 518, 231259.CrossRefGoogle Scholar
Sullivan, R., Wilde, B., Noble, D. R., Seitzman, J. M. & Lieuwen, T. C. 2014 Time-averaged characteristics of a reacting fuel jet in vitiated cross-flow. Combust. Flame 161 (7), 17921803.CrossRefGoogle Scholar
Thévenin, D. & Candel, S. 1995 Ignition dynamics of a diffusion flame rolled up in a vortex. Phys. Fluids 7 (2), 434445.CrossRefGoogle Scholar
Vanquickenborne, L. & van Tiggelen, A. 1966 The stabilization mechanism of lifted diffusion flames. Combust. Flame 10 (1), 5969.CrossRefGoogle Scholar
Viggiano, A. 2004 A 2-D investigation of n-heptane autoignition by means of direct numerical simulation. Combust. Flame 137 (4), 432443.CrossRefGoogle Scholar
Viggiano, A. 2010 Exploring the effect of fluid dynamics and kinetic mechanisms on n-heptane autoignition in transient jets. Combust. Flame 157 (2), 328340.CrossRefGoogle Scholar
Wang, Y. & Rutland, C. J. 2007 Direct numerical simulation of ignition in turbulent n -heptane liquid-fuel spray jets. Combust. Flame 149 (4), 353365.CrossRefGoogle Scholar
Yoo, C. S., Richardson, E. S., Sankaran, R. & Chen, J. H. 2011 A DNS study on the stabilization mechanism of a turbulent lifted ethylene jet flame in highly-heated coflow. Proc. Combust. Inst. 33 (1), 16191627.CrossRefGoogle Scholar
Yoo, C. S., Sankaran, R. & Chen, J. H. 2009 Three-dimensional direct numerical simulation of a turbulent lifted hydrogen jet flame in heated coflow: flame stabilization and structure. J. Fluid Mech. 640, 453481.CrossRefGoogle Scholar
36
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Two-stage autoignition and edge flames in a high pressure turbulent jet
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Two-stage autoignition and edge flames in a high pressure turbulent jet
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Two-stage autoignition and edge flames in a high pressure turbulent jet
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *