Yuriy Shoshin - Academia.edu (original) (raw)

Papers by Yuriy Shoshin

Research paper thumbnail of Size evolution during laser-ignited single iron particle combustion

Proceedings of the Combustion Institute

Research paper thumbnail of Flame Stabilization and Blow-Off of Ultra-Lean H2-Air Premixed Flames

Energies

The manner in which an ultra-lean hydrogen flame stabilizes and blows off is crucial for the unde... more The manner in which an ultra-lean hydrogen flame stabilizes and blows off is crucial for the understanding and design of safe and efficient combustion devices. In this study, we use experiments and numerical simulations for pure H2-air flames stabilized behind a cylindrical bluff body to reveal the underlying physics that make such flames stable and eventually blow-off. Results from CFD simulations are used to investigate the role of stretch and preferential diffusion after a qualitative validation with experiments. It is found that the flame displacement speed of flames stabilized beyond the lean flammability limit of a flat stretchless flame (ϕ=0.3) can be scaled with a relevant tubular flame displacement speed. This result is crucial as no scaling reference is available for such flames. We also confirm our previous hypothesis regarding lean limit blow-off for flames with a neck formation that such flames are quenched due to excessive local stretching. After extinction at the flam...

Research paper thumbnail of Experimental study of the structure of the lean two-dimensional hydrogen-methane-air Bunsen flame tip with implications to turbulent flames

Flame cusps, or folds, which form on concave fragments of turbulent flames are locations of stron... more Flame cusps, or folds, which form on concave fragments of turbulent flames are locations of strong negative flame stretch. In mixtures with non-unity Lewis number, in particular, in hydrogen-containing mixtures, local flame stretching induces preferential diffusion, which may affect such practically important characteristics as local burning velocity, flame temperature and reaction rates. In present work, the detailed structure of flame cusps represented by the tip of 2-dimensional laminar Bunsen flames of lean (H2+CH4)-air mixtures has been studied experimentally using spontaneous Raman scattering. Introduction When curved flames propagate into a fresh mixture of reactants, cusps may form on concave fragments of the flame front as a result of the local flame front propagation relative to the gas. In particular, cusps are commonly formed in turbulent flames, because the flame front is deformed by the turbulent flow. Cusp formation is intensified in mixtures with Lewis numbers less t...

Research paper thumbnail of Temperature and phase transitions of laser-ignited single iron particle

Combustion and Flame, 2022

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Quantifying the impact of heat loss, stretch and preferential diffusion effects to the anchoring of bluff body stabilized premixed flames

Combustion and Flame, 2021

Abstract The response of a premixed flame subjected to either flame stretch (and associated Lewis... more Abstract The response of a premixed flame subjected to either flame stretch (and associated Lewis number effects) or heat loss has been well documented in the literature and has enabled a good understanding of canonical configurations such as flat burner-stabilized, counter flow and tubular flames. However, in practical burners, flames are simultaneously subjected to stretch, heat transfer with the flame holder and preferential diffusion effects. For such flames, usually the collective effect of underlying contributions is studied and individual effects are only treated in a qualitative manner. In this paper, our objective is to use flame stretch theory to separate and quantify the underlying contributions from flame stretch, preferential diffusion and heat transfer with the flame holder to the flame speed of bluff body stabilized flames. It is shown that the theory adequately predicts the flame displacement speed in comparison to the results from the numerical simulations. Using the quantification of contributions, an overall stabilization mechanism for H 2 enriched CH 4 -air mixtures is discussed. The role of competing contributions from preferential diffusion and heat loss is highlighted especially near the flame base region where the flame speed is heavily impacted by all the effects. Insights are also given for low Lewis number flashback prone flames.

Research paper thumbnail of A physical relationship between consumption and displacement speed for premixed flames with finite thickness

Proceedings of the Combustion Institute, 2021

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Flame stabilization regimes for premixed flames anchored behind cylindrical flame holders

Proceedings of the Combustion Institute, 2020

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Percolating Reaction–Diffusion Waves (PERWAVES)—Sounding rocket combustion experiments

Acta Astronautica, 2020

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Numerical and experimental studies of torus-like flame around the vortex filament in a premixed reactant flow

Combustion Science and Technology, 2018

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Structure and stability of premixed flames stabilized behind the trailing edge of a cylindrical rod at low Lewis numbers

Proceedings of the Combustion Institute, 2015

Structure and stability of premixed flames stabilized behind the trailing edge of a cylindrical r... more Structure and stability of premixed flames stabilized behind the trailing edge of a cylindrical rod at low Lewis numbers.

Research paper thumbnail of Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

Combustion Theory and Modelling, 2017

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Formation, prediction and analysis of stationary and stable ball-like flames at ultra-lean and normal-gravity conditions

Combustion and Flame, 2015

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Laminar Lifted Flame Velocity Measurements for Aerosols of Metals and Mechanical Alloys

41st Aerospace Sciences Meeting and Exhibit, 2003

Research paper thumbnail of Reaction mechanisms and particle interaction in burning two-phase systems

Research paper thumbnail of Two-line atomic fluorescence thermometry in the saturation regime

Applied Physics B, 2014

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of On extinction mechanism of lean limit methane–air flame in a standard flammability tube

Proceedings of the Combustion Institute, 2009

Gas-dynamic and qualitative thermal structure of lean methane-air flames propagating upward in a ... more Gas-dynamic and qualitative thermal structure of lean methane-air flames propagating upward in a standard flammability tube has been experimentally investigated at near-limit concentrations. Local burning velocity related to the cold and hot flame boundaries, and stretch rates have been measured along studied flames. The measured stretch rate attains its maximum value at the flame tip. It was experimentally found that flame temperature is minimum at the flame tip, which agrees with the observation that flame extinction starts from the leading point, but cannot be explained by the combined effect of stretch rate and preferential diffusion. In the coordinate system moving with the flame, a zone of stagnation of combustion products was observed in limit flame near its tip, while at higher methane concentrations stagnation zone does not exist. This observation suggests that limit flame extinction behavior is connected with the formation of the stagnation zone: leading edge of the flame can be cooled by heat conduction to the stagnation zone, which rises upward together with flame and is effectively cooled due to radiation heat loss. Simplified analysis of this effect in a single stretched flame is carried out in terms of coupling radiation losses with local stretch rate. It was found that flame is accompanied by a rising upward combustion products flow, resembling a hot bubble and located about 35 cm downstream of the flame.

Research paper thumbnail of Effect of the discrete nature of heat sources on flame propagation in particulate suspensions

Symposium (International) on Combustion, 1998

ABSTRACT

Research paper thumbnail of Constant pressure flames of aluminum and aluminum-magnesium mechanical alloy aerosols in microgravity

Combustion and Flame, 2002

In an effort to develop new aluminum-basedenergetic materials for advanced metallizedpropellants,... more In an effort to develop new aluminum-basedenergetic materials for advanced metallizedpropellants, explosives, pyrotechnics, and incen-diaries, metastable Al-Mg mechanical alloyshave been recently prepared and characterized[1]. In this work, the experimental setup de-signed for the constant pressure experiments onaerosol flame propagation in microgravity [2–4]was exploited to compare the flame propagationin the aerosols of pure Al versus Al-Mg me-chanical alloys. In addition, combustion prod-ucts produced with different metallic fuels werecollected and compared with one another.

Research paper thumbnail of Ignition of aluminum-rich Al–Ti mechanical alloys in air

Combustion and Flame, 2006

Ignition of metastable Al-Ti mechanical alloys with titanium concentrations from 10 to 25 at% was... more Ignition of metastable Al-Ti mechanical alloys with titanium concentrations from 10 to 25 at% was investigated experimentally. A thin layer of powder was coated on an electrically heated filament. The ignition instant was identified from the powder's radiation measured in real time. Simultaneously, filament temperatures were measured using a high-speed infrared pyrometer to determine the ignition temperature. The experiments were conducted at different filament heating rates in the range of 3 × 10 3-2 × 10 4 K/s to determine the ignition kinetics. The ignition temperatures and kinetics were compared to the respective characteristics of the phase changes and oxidation steps observed for the same mechanical alloys using thermal analysis. It was shown that at the heating rates exceeding 10 3 K/s, the exothermic formation of a metastable L1 2 phase of Al 3 Ti occurring during heating of the Al-Ti mechanical alloys triggers their ignition. This conclusion was confirmed by additional ignition experiments in which annealed mechanical alloys already containing this transition Al 3 Ti phase did not ignite in the same temperature range as fresh mechanical alloys. The ignition kinetics identified for Al-Ti mechanical alloys based on thermal analysis and on ignition experiments enables one to predict ignition temperatures as a function of both composition and heating rate. Specifically, extrapolation is possible to higher heating rates typical for aerosol flames.

Research paper thumbnail of Particle combustion rates in premixed flames of polydisperse metal—air aerosols

Combustion and Flame, 2003

A new approach and experimental technique are proposed to determine times of metal particle combu... more A new approach and experimental technique are proposed to determine times of metal particle combustion in flames of polydisperse aerosols. Laminar flames are produced in air at 1 atm, using aerosol jets formed by an electrostatic particulate method. The flame radiation intensities as a function of vertical coordinate are measured and compared with the flame radiation profiles reconstructed using experimental data and simplified models. The experimental data used include particle size distributions, flame velocities, and temperatures of metal ignition and combustion. The simplified models describe the particle ignition delay, combustion time, and particle flame radiation intensity as a function of particle diameter, D. Variable parameters of the models describing particle radiation intensities and combustion times are adjusted to achieve the best fit between the reconstructed and measured flame radiation profiles. A set of parameters providing the best agreement between the reconstructed and measured profiles is selected for several aerosol flames produced by powders of different sizes of the same material. These parameters are assumed to adequately describe particle combustion times and radiation intensities for the chosen material. The experimental radiation profiles for both aluminum and magnesium aerosol flames with particles of different sizes were found to be in very good agreement with the respective reconstructed profiles. For both metals, particle radiation intensities were well described by a D 3-type expression. The combustion times for magnesium aerosol particles were well described by the traditional D 2-law with the evaporation constant close to those reported earlier for single particles. Aluminum aerosol particle combustion was better described by a D 1-law and combustion times of fine (Ͻ80 m) aluminum particles in the aerosol were somewhat longer than the reported earlier combustion times for single aluminum particles.

Research paper thumbnail of Size evolution during laser-ignited single iron particle combustion

Proceedings of the Combustion Institute

Research paper thumbnail of Flame Stabilization and Blow-Off of Ultra-Lean H2-Air Premixed Flames

Energies

The manner in which an ultra-lean hydrogen flame stabilizes and blows off is crucial for the unde... more The manner in which an ultra-lean hydrogen flame stabilizes and blows off is crucial for the understanding and design of safe and efficient combustion devices. In this study, we use experiments and numerical simulations for pure H2-air flames stabilized behind a cylindrical bluff body to reveal the underlying physics that make such flames stable and eventually blow-off. Results from CFD simulations are used to investigate the role of stretch and preferential diffusion after a qualitative validation with experiments. It is found that the flame displacement speed of flames stabilized beyond the lean flammability limit of a flat stretchless flame (ϕ=0.3) can be scaled with a relevant tubular flame displacement speed. This result is crucial as no scaling reference is available for such flames. We also confirm our previous hypothesis regarding lean limit blow-off for flames with a neck formation that such flames are quenched due to excessive local stretching. After extinction at the flam...

Research paper thumbnail of Experimental study of the structure of the lean two-dimensional hydrogen-methane-air Bunsen flame tip with implications to turbulent flames

Flame cusps, or folds, which form on concave fragments of turbulent flames are locations of stron... more Flame cusps, or folds, which form on concave fragments of turbulent flames are locations of strong negative flame stretch. In mixtures with non-unity Lewis number, in particular, in hydrogen-containing mixtures, local flame stretching induces preferential diffusion, which may affect such practically important characteristics as local burning velocity, flame temperature and reaction rates. In present work, the detailed structure of flame cusps represented by the tip of 2-dimensional laminar Bunsen flames of lean (H2+CH4)-air mixtures has been studied experimentally using spontaneous Raman scattering. Introduction When curved flames propagate into a fresh mixture of reactants, cusps may form on concave fragments of the flame front as a result of the local flame front propagation relative to the gas. In particular, cusps are commonly formed in turbulent flames, because the flame front is deformed by the turbulent flow. Cusp formation is intensified in mixtures with Lewis numbers less t...

Research paper thumbnail of Temperature and phase transitions of laser-ignited single iron particle

Combustion and Flame, 2022

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Quantifying the impact of heat loss, stretch and preferential diffusion effects to the anchoring of bluff body stabilized premixed flames

Combustion and Flame, 2021

Abstract The response of a premixed flame subjected to either flame stretch (and associated Lewis... more Abstract The response of a premixed flame subjected to either flame stretch (and associated Lewis number effects) or heat loss has been well documented in the literature and has enabled a good understanding of canonical configurations such as flat burner-stabilized, counter flow and tubular flames. However, in practical burners, flames are simultaneously subjected to stretch, heat transfer with the flame holder and preferential diffusion effects. For such flames, usually the collective effect of underlying contributions is studied and individual effects are only treated in a qualitative manner. In this paper, our objective is to use flame stretch theory to separate and quantify the underlying contributions from flame stretch, preferential diffusion and heat transfer with the flame holder to the flame speed of bluff body stabilized flames. It is shown that the theory adequately predicts the flame displacement speed in comparison to the results from the numerical simulations. Using the quantification of contributions, an overall stabilization mechanism for H 2 enriched CH 4 -air mixtures is discussed. The role of competing contributions from preferential diffusion and heat loss is highlighted especially near the flame base region where the flame speed is heavily impacted by all the effects. Insights are also given for low Lewis number flashback prone flames.

Research paper thumbnail of A physical relationship between consumption and displacement speed for premixed flames with finite thickness

Proceedings of the Combustion Institute, 2021

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Flame stabilization regimes for premixed flames anchored behind cylindrical flame holders

Proceedings of the Combustion Institute, 2020

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Percolating Reaction–Diffusion Waves (PERWAVES)—Sounding rocket combustion experiments

Acta Astronautica, 2020

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Numerical and experimental studies of torus-like flame around the vortex filament in a premixed reactant flow

Combustion Science and Technology, 2018

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Structure and stability of premixed flames stabilized behind the trailing edge of a cylindrical rod at low Lewis numbers

Proceedings of the Combustion Institute, 2015

Structure and stability of premixed flames stabilized behind the trailing edge of a cylindrical r... more Structure and stability of premixed flames stabilized behind the trailing edge of a cylindrical rod at low Lewis numbers.

Research paper thumbnail of Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

Combustion Theory and Modelling, 2017

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Formation, prediction and analysis of stationary and stable ball-like flames at ultra-lean and normal-gravity conditions

Combustion and Flame, 2015

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of Laminar Lifted Flame Velocity Measurements for Aerosols of Metals and Mechanical Alloys

41st Aerospace Sciences Meeting and Exhibit, 2003

Research paper thumbnail of Reaction mechanisms and particle interaction in burning two-phase systems

Research paper thumbnail of Two-line atomic fluorescence thermometry in the saturation regime

Applied Physics B, 2014

DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Research paper thumbnail of On extinction mechanism of lean limit methane–air flame in a standard flammability tube

Proceedings of the Combustion Institute, 2009

Gas-dynamic and qualitative thermal structure of lean methane-air flames propagating upward in a ... more Gas-dynamic and qualitative thermal structure of lean methane-air flames propagating upward in a standard flammability tube has been experimentally investigated at near-limit concentrations. Local burning velocity related to the cold and hot flame boundaries, and stretch rates have been measured along studied flames. The measured stretch rate attains its maximum value at the flame tip. It was experimentally found that flame temperature is minimum at the flame tip, which agrees with the observation that flame extinction starts from the leading point, but cannot be explained by the combined effect of stretch rate and preferential diffusion. In the coordinate system moving with the flame, a zone of stagnation of combustion products was observed in limit flame near its tip, while at higher methane concentrations stagnation zone does not exist. This observation suggests that limit flame extinction behavior is connected with the formation of the stagnation zone: leading edge of the flame can be cooled by heat conduction to the stagnation zone, which rises upward together with flame and is effectively cooled due to radiation heat loss. Simplified analysis of this effect in a single stretched flame is carried out in terms of coupling radiation losses with local stretch rate. It was found that flame is accompanied by a rising upward combustion products flow, resembling a hot bubble and located about 35 cm downstream of the flame.

Research paper thumbnail of Effect of the discrete nature of heat sources on flame propagation in particulate suspensions

Symposium (International) on Combustion, 1998

ABSTRACT

Research paper thumbnail of Constant pressure flames of aluminum and aluminum-magnesium mechanical alloy aerosols in microgravity

Combustion and Flame, 2002

In an effort to develop new aluminum-basedenergetic materials for advanced metallizedpropellants,... more In an effort to develop new aluminum-basedenergetic materials for advanced metallizedpropellants, explosives, pyrotechnics, and incen-diaries, metastable Al-Mg mechanical alloyshave been recently prepared and characterized[1]. In this work, the experimental setup de-signed for the constant pressure experiments onaerosol flame propagation in microgravity [2–4]was exploited to compare the flame propagationin the aerosols of pure Al versus Al-Mg me-chanical alloys. In addition, combustion prod-ucts produced with different metallic fuels werecollected and compared with one another.

Research paper thumbnail of Ignition of aluminum-rich Al–Ti mechanical alloys in air

Combustion and Flame, 2006

Ignition of metastable Al-Ti mechanical alloys with titanium concentrations from 10 to 25 at% was... more Ignition of metastable Al-Ti mechanical alloys with titanium concentrations from 10 to 25 at% was investigated experimentally. A thin layer of powder was coated on an electrically heated filament. The ignition instant was identified from the powder's radiation measured in real time. Simultaneously, filament temperatures were measured using a high-speed infrared pyrometer to determine the ignition temperature. The experiments were conducted at different filament heating rates in the range of 3 × 10 3-2 × 10 4 K/s to determine the ignition kinetics. The ignition temperatures and kinetics were compared to the respective characteristics of the phase changes and oxidation steps observed for the same mechanical alloys using thermal analysis. It was shown that at the heating rates exceeding 10 3 K/s, the exothermic formation of a metastable L1 2 phase of Al 3 Ti occurring during heating of the Al-Ti mechanical alloys triggers their ignition. This conclusion was confirmed by additional ignition experiments in which annealed mechanical alloys already containing this transition Al 3 Ti phase did not ignite in the same temperature range as fresh mechanical alloys. The ignition kinetics identified for Al-Ti mechanical alloys based on thermal analysis and on ignition experiments enables one to predict ignition temperatures as a function of both composition and heating rate. Specifically, extrapolation is possible to higher heating rates typical for aerosol flames.

Research paper thumbnail of Particle combustion rates in premixed flames of polydisperse metal—air aerosols

Combustion and Flame, 2003

A new approach and experimental technique are proposed to determine times of metal particle combu... more A new approach and experimental technique are proposed to determine times of metal particle combustion in flames of polydisperse aerosols. Laminar flames are produced in air at 1 atm, using aerosol jets formed by an electrostatic particulate method. The flame radiation intensities as a function of vertical coordinate are measured and compared with the flame radiation profiles reconstructed using experimental data and simplified models. The experimental data used include particle size distributions, flame velocities, and temperatures of metal ignition and combustion. The simplified models describe the particle ignition delay, combustion time, and particle flame radiation intensity as a function of particle diameter, D. Variable parameters of the models describing particle radiation intensities and combustion times are adjusted to achieve the best fit between the reconstructed and measured flame radiation profiles. A set of parameters providing the best agreement between the reconstructed and measured profiles is selected for several aerosol flames produced by powders of different sizes of the same material. These parameters are assumed to adequately describe particle combustion times and radiation intensities for the chosen material. The experimental radiation profiles for both aluminum and magnesium aerosol flames with particles of different sizes were found to be in very good agreement with the respective reconstructed profiles. For both metals, particle radiation intensities were well described by a D 3-type expression. The combustion times for magnesium aerosol particles were well described by the traditional D 2-law with the evaporation constant close to those reported earlier for single particles. Aluminum aerosol particle combustion was better described by a D 1-law and combustion times of fine (Ͻ80 m) aluminum particles in the aerosol were somewhat longer than the reported earlier combustion times for single aluminum particles.