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

IF 6.4 2区工程技术 Q1 THERMODYNAMICS

Case Studies in Thermal Engineering Pub Date : 2025-01-07 DOI:10.1016/j.csite.2025.105751

Vinay Sankar, Ratna Kishore Velamati, Sudipto Mukhopadhyay

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Abstract

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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来源期刊

Case Studies in Thermal Engineering Chemical Engineering-Fluid Flow and Transfer Processes

CiteScore

8.60

自引率

11.80%

发文量

812

审稿时长

76 days

期刊介绍： Case Studies in Thermal Engineering provides a forum for the rapid publication of short, structured Case Studies in Thermal Engineering and related Short Communications. It provides an essential compendium of case studies for researchers and practitioners in the field of thermal engineering and others who are interested in aspects of thermal engineering cases that could affect other engineering processes. The journal not only publishes new and novel case studies, but also provides a forum for the publication of high quality descriptions of classic thermal engineering problems. The scope of the journal includes case studies of thermal engineering problems in components, devices and systems using existing experimental and numerical techniques in the areas of mechanical, aerospace, chemical, medical, thermal management for electronics, heat exchangers, regeneration, solar thermal energy, thermal storage, building energy conservation, and power generation. Case studies of thermal problems in other areas will also be considered.