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Jetting Dynamics of Burning Gel Fuel Droplets

Jetting in burning gel fuel droplets is an important process which, in addition to pure vaporization, enables the convective transport of unreacted fuel vapors from the droplet interior to the flame envelope. This aids in accelerating the fuel efflux and enhancing the mixing of the gas phase, which...

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Autores principales: Sharma, Janmejai, Miglani, Ankur, John, Jerin, Nandagopalan, Purushothaman, Shaikh, Javed, Kankar, Pavan Kumar
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9777847/
https://www.ncbi.nlm.nih.gov/pubmed/36547304
http://dx.doi.org/10.3390/gels8120781
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author Sharma, Janmejai
Miglani, Ankur
John, Jerin
Nandagopalan, Purushothaman
Shaikh, Javed
Kankar, Pavan Kumar
author_facet Sharma, Janmejai
Miglani, Ankur
John, Jerin
Nandagopalan, Purushothaman
Shaikh, Javed
Kankar, Pavan Kumar
author_sort Sharma, Janmejai
collection PubMed
description Jetting in burning gel fuel droplets is an important process which, in addition to pure vaporization, enables the convective transport of unreacted fuel vapors from the droplet interior to the flame envelope. This aids in accelerating the fuel efflux and enhancing the mixing of the gas phase, which improves the droplet burn rates. In this study, Schlieren imaging was used to characterize different jetting dynamics that govern the combustion behavior of organic-gellant-laden ethanol gel fuel droplets. To initiate jetting, the gellant shell of the burning gel fuel droplet was subjected to either oscillatory bursting or isolated bursting, or both. However, irrespective of the jetting mode, the jets interacted with the flame envelope in one of three possible ways. Based on the velocity and the degree to which a jet disrupts the flame envelope, it is classified as either a flame distortion, a fire ball outside the flame or a pin hole jet (localized flame extinction), where the pin hole jets have the highest velocity (1000–1550 mm/s), while the flame distortion events have the lowest velocity (500–870 mm/s). Subsequently, the relative number of the three types of jetting events during the droplet lifetime was analyzed as a function of the type of organic gellant. It was demonstrated that the combustion behavior of gel fuels (hydroxypropyl methylcellulose: HPMC at 3 wt.%) that tend to form thin-weak-flexible shells is dominated by low-velocity flame distortion events, while the gel fuels (methylcellulose: MC at 9 wt.%) that facilitate the formation of thick-strong-rigid shells are governed by high-velocity fire ball and pin hole jets. Overall, this study provides critical insights into the jetting behavior and its characterization, which can help us to tune the droplet gasification and the gas phase mixing to achieve an effective combustion control strategy for gel fuels.
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spelling pubmed-97778472022-12-23 Jetting Dynamics of Burning Gel Fuel Droplets Sharma, Janmejai Miglani, Ankur John, Jerin Nandagopalan, Purushothaman Shaikh, Javed Kankar, Pavan Kumar Gels Article Jetting in burning gel fuel droplets is an important process which, in addition to pure vaporization, enables the convective transport of unreacted fuel vapors from the droplet interior to the flame envelope. This aids in accelerating the fuel efflux and enhancing the mixing of the gas phase, which improves the droplet burn rates. In this study, Schlieren imaging was used to characterize different jetting dynamics that govern the combustion behavior of organic-gellant-laden ethanol gel fuel droplets. To initiate jetting, the gellant shell of the burning gel fuel droplet was subjected to either oscillatory bursting or isolated bursting, or both. However, irrespective of the jetting mode, the jets interacted with the flame envelope in one of three possible ways. Based on the velocity and the degree to which a jet disrupts the flame envelope, it is classified as either a flame distortion, a fire ball outside the flame or a pin hole jet (localized flame extinction), where the pin hole jets have the highest velocity (1000–1550 mm/s), while the flame distortion events have the lowest velocity (500–870 mm/s). Subsequently, the relative number of the three types of jetting events during the droplet lifetime was analyzed as a function of the type of organic gellant. It was demonstrated that the combustion behavior of gel fuels (hydroxypropyl methylcellulose: HPMC at 3 wt.%) that tend to form thin-weak-flexible shells is dominated by low-velocity flame distortion events, while the gel fuels (methylcellulose: MC at 9 wt.%) that facilitate the formation of thick-strong-rigid shells are governed by high-velocity fire ball and pin hole jets. Overall, this study provides critical insights into the jetting behavior and its characterization, which can help us to tune the droplet gasification and the gas phase mixing to achieve an effective combustion control strategy for gel fuels. MDPI 2022-11-29 /pmc/articles/PMC9777847/ /pubmed/36547304 http://dx.doi.org/10.3390/gels8120781 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Sharma, Janmejai
Miglani, Ankur
John, Jerin
Nandagopalan, Purushothaman
Shaikh, Javed
Kankar, Pavan Kumar
Jetting Dynamics of Burning Gel Fuel Droplets
title Jetting Dynamics of Burning Gel Fuel Droplets
title_full Jetting Dynamics of Burning Gel Fuel Droplets
title_fullStr Jetting Dynamics of Burning Gel Fuel Droplets
title_full_unstemmed Jetting Dynamics of Burning Gel Fuel Droplets
title_short Jetting Dynamics of Burning Gel Fuel Droplets
title_sort jetting dynamics of burning gel fuel droplets
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9777847/
https://www.ncbi.nlm.nih.gov/pubmed/36547304
http://dx.doi.org/10.3390/gels8120781
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AT shaikhjaved jettingdynamicsofburninggelfueldroplets
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