{"title":"New insights into the pre-ignition behavior of methane behind reflected shock waves","authors":"J. Caravaca-Vilchez, K. A. Heufer","doi":"10.1007/s00193-023-01130-9","DOIUrl":null,"url":null,"abstract":"<div><p>Pre-ignition is an undesired combustion event known to restrict kinetic modeling validation. Previous methane oxidation studies reported premature ignition as part of ignition delay time measurements in shock tubes. In this context, the effect on the pre-ignition propensity and auto-ignition behavior of stoichiometric methane mixtures at different dilution levels of <span>\\(\\hbox {N}_2\\)</span>, Ar, He, and <span>\\(\\hbox {CO}_2\\)</span> was studied at 10 bar and 25 bar and temperatures between 1080 K and 1350 K. In addition to conventional sidewall pressure and endwall light emission measurements, a high-speed imaging setup was utilized to visualize the ignition process. Relevant physicochemical parameters to describe and predict the pre-ignition phenomenon were used. The results suggest that dilution levels up to <span>\\(80\\%\\)</span> of bath gas are not successful in mitigating early ignition occurrence and its effects at moderate pressures. Replacing <span>\\(\\hbox {N}_2\\)</span> by He was found to suppress early ignition at 10 bar, attributed to an enhanced dissipation of temperature inhomogeneities in the test gas section. The present findings demonstrate that <span>\\(\\hbox {CO}_2\\)</span> has potential for pre-ignition heat release mitigation, while Ar was confirmed to promote premature ignition. To the best of our knowledge, we present the first detailed study on pre-ignition mitigation for methane mixtures in shock tubes, where further insights into its ignition non-idealities are given.\n</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7000,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01130-9.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Shock Waves","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s00193-023-01130-9","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
Abstract
Pre-ignition is an undesired combustion event known to restrict kinetic modeling validation. Previous methane oxidation studies reported premature ignition as part of ignition delay time measurements in shock tubes. In this context, the effect on the pre-ignition propensity and auto-ignition behavior of stoichiometric methane mixtures at different dilution levels of \(\hbox {N}_2\), Ar, He, and \(\hbox {CO}_2\) was studied at 10 bar and 25 bar and temperatures between 1080 K and 1350 K. In addition to conventional sidewall pressure and endwall light emission measurements, a high-speed imaging setup was utilized to visualize the ignition process. Relevant physicochemical parameters to describe and predict the pre-ignition phenomenon were used. The results suggest that dilution levels up to \(80\%\) of bath gas are not successful in mitigating early ignition occurrence and its effects at moderate pressures. Replacing \(\hbox {N}_2\) by He was found to suppress early ignition at 10 bar, attributed to an enhanced dissipation of temperature inhomogeneities in the test gas section. The present findings demonstrate that \(\hbox {CO}_2\) has potential for pre-ignition heat release mitigation, while Ar was confirmed to promote premature ignition. To the best of our knowledge, we present the first detailed study on pre-ignition mitigation for methane mixtures in shock tubes, where further insights into its ignition non-idealities are given.
期刊介绍:
Shock Waves provides a forum for presenting and discussing new results in all fields where shock and detonation phenomena play a role. The journal addresses physicists, engineers and applied mathematicians working on theoretical, experimental or numerical issues, including diagnostics and flow visualization.
The research fields considered include, but are not limited to, aero- and gas dynamics, acoustics, physical chemistry, condensed matter and plasmas, with applications encompassing materials sciences, space sciences, geosciences, life sciences and medicine.
Of particular interest are contributions which provide insights into fundamental aspects of the techniques that are relevant to more than one specific research community.
The journal publishes scholarly research papers, invited review articles and short notes, as well as comments on papers already published in this journal. Occasionally concise meeting reports of interest to the Shock Waves community are published.