Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustor

An experimental study was performed to explore the flammability limits of ethanol fuelled stepped micro-combustor (three-step) at different scales (by changing surface area to volume ratio (S/V)). The combustors were made of quartz, stainless steel, and aluminium, each with a thermal conductivity th...

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Main Authors: Vinay Sankar, Ratna Kishore Velamati, Sudipto Mukhopadhyay
Format: Article
Language:English
Published: Elsevier 2025-02-01
Series:Case Studies in Thermal Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214157X25000115
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author Vinay Sankar
Ratna Kishore Velamati
Sudipto Mukhopadhyay
author_facet Vinay Sankar
Ratna Kishore Velamati
Sudipto Mukhopadhyay
author_sort Vinay Sankar
collection DOAJ
description An experimental study was performed to explore the flammability limits of ethanol fuelled stepped micro-combustor (three-step) at different scales (by changing surface area to volume ratio (S/V)). The combustors were made of quartz, stainless steel, and aluminium, each with a thermal conductivity that differed by order of magnitude. The study indicates that reducing the S/V, leads to upstream flame stabilization, with aluminium combustors having superior flame stabilization nearer to the combustor inlet followed by stainless steel and quartz combustors. It was observed that for all scales of combustors, better blowout limit and flashback limit were observed at ϕ=1.1. Interestingly the blowout limit followed a trend similar to that of laminar burning velocity (SL) and the flashback limit followed a trend similar to temperature dependency (α) of SL with ϕ. The aluminium combustors at all scales showed better outer wall mean temperature (Tmean) and uniformity (σT), making it more suitable for Thermoelectric Generator (TEG) applications. The uniform wall temperature distribution in the aluminium combustor allows for the mounting of more TEG modules compared to Stainless steel combustors, where TEG modules can only be effectively mounted on the second and third steps due to non-uniform wall temperatures in the first step.
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spelling doaj-art-29c626635e4f457f9e18801d0ccf53922025-02-02T05:27:21ZengElsevierCase Studies in Thermal Engineering2214-157X2025-02-0166105751Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustorVinay Sankar0Ratna Kishore Velamati1Sudipto Mukhopadhyay2Department of Mechanical Engineering, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342030, IndiaDepartment of Mechanical Engineering, Amrita School of Engineering, Coimbatore, Amrita Vishwa Vidyapeetham, Tamil-Nadu, 641112, India; Corresponding authors.Department of Mechanical Engineering, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342030, India; Corresponding authors.An experimental study was performed to explore the flammability limits of ethanol fuelled stepped micro-combustor (three-step) at different scales (by changing surface area to volume ratio (S/V)). The combustors were made of quartz, stainless steel, and aluminium, each with a thermal conductivity that differed by order of magnitude. The study indicates that reducing the S/V, leads to upstream flame stabilization, with aluminium combustors having superior flame stabilization nearer to the combustor inlet followed by stainless steel and quartz combustors. It was observed that for all scales of combustors, better blowout limit and flashback limit were observed at ϕ=1.1. Interestingly the blowout limit followed a trend similar to that of laminar burning velocity (SL) and the flashback limit followed a trend similar to temperature dependency (α) of SL with ϕ. The aluminium combustors at all scales showed better outer wall mean temperature (Tmean) and uniformity (σT), making it more suitable for Thermoelectric Generator (TEG) applications. The uniform wall temperature distribution in the aluminium combustor allows for the mounting of more TEG modules compared to Stainless steel combustors, where TEG modules can only be effectively mounted on the second and third steps due to non-uniform wall temperatures in the first step.http://www.sciencedirect.com/science/article/pii/S2214157X25000115Micro/meso scale combustorStepped combustorEthanolPremixedPower generation
spellingShingle Vinay Sankar
Ratna Kishore Velamati
Sudipto Mukhopadhyay
Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustor
Case Studies in Thermal Engineering
Micro/meso scale combustor
Stepped combustor
Ethanol
Premixed
Power generation
title Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustor
title_full Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustor
title_fullStr Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustor
title_full_unstemmed Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustor
title_short Experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro-combustor
title_sort experimental and numerical studies on scaling and thermal conductivity of backward step ethanol fueled micro combustor
topic Micro/meso scale combustor
Stepped combustor
Ethanol
Premixed
Power generation
url http://www.sciencedirect.com/science/article/pii/S2214157X25000115
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AT ratnakishorevelamati experimentalandnumericalstudiesonscalingandthermalconductivityofbackwardstepethanolfueledmicrocombustor
AT sudiptomukhopadhyay experimentalandnumericalstudiesonscalingandthermalconductivityofbackwardstepethanolfueledmicrocombustor