Simulating the Effect of Electric Bias Voltages on the Electrical Characteristics of Oxyfuel Preheat Flame Using Reduced Combustion Mechanism
Simulating the Effect of Electric Bias Voltages on the Electrical Characteristics of Oxyfuel Preheat Flame Using Reduced Combustion Mechanism
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利用还原燃烧机制模拟电偏压对富氧预热火焰电特性的影响
DOI：
10.1115/1.4062963
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Martin, Christopher R.
中科院分区：
文献类型：
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作者：
Rahman, S. M.;Warrier, Rohith;Untaroiu, Alexandrina;Martin, Christopher R.
本文建立了一个三维计算模型，详细描述了预混甲烷-氧气切割火焰在偏压作用下预热过程的电气特性和电流-电压关系。因此，描述燃烧、带电物质的电化学传输和电势的方程通过可商购的有限体积计算流体动力学（CFD）代码求解。甲烷-氧气（CH 4-O2）火焰的反应与还原机制相结合，并产生三种化学离子H3 O+，HCO+和e-的额外电离反应，以描述火焰中离子的化学性质。研究了在V ∈ [−5 V，+5 V]范围内的离子迁移和离子分布等电学特性。由于物理火焰是由12本生一样的锥形火焰，包括第三维赋予的分辨率的流体力学和相互作用之间的各个圆锥。得出的结论是，带电的“鞘”形成在焊炬和工件表面，随后形成三个不同的制度中的i-v关系。从这项研究中获得的i-v特性进行了比较，以前的实验和二维计算模型的预混火焰。通过这种方式，整个模型产生了对氧燃料切割火焰的物理行为的更好理解，沿着有更有效的i-v特性。这种理解可能会提供关键信息，实现自主的氧气切割过程。
A three-dimensional computational model is presented in this paper that illustrates the detailed electrical characteristics, and the current–voltage (i–v) relationship throughout the preheating process of premixed methane-oxygen oxyfuel cutting flame subject to electric bias voltages. As such, the equations describing combustion, electrochemical transport for charged species, and potential are solved through a commercially available finite volume computational fluid dynamics (CFD) code. The reactions of the methane-oxygen (CH4–O2) flame were combined with a reduced mechanism, and additional ionization reactions that generate three chemi-ions, H3O+, HCO+, and e−, to describe the chemistry of ions in flames. The electrical characteristics such as ion migrations and ion distributions are investigated for a range of electric potential, V ∈ [−5 V, +5 V]. Since the physical flame is comprised of twelve Bunsen-like conical flames, inclusion of the third dimension imparts the resolution of fluid mechanics and the interaction among the individual cones. It was concluded that charged “sheaths” are formed at both torch and workpiece surfaces, subsequently forming three distinct regimes in the i–v relationship. The i–v characteristics obtained from this study have been compared to the previous experimental and two-dimensional computational model for premixed flame. In this way, the overall model generates a better understanding of the physical behavior of the oxyfuel-cutting flames, along with more validated i–v characteristics. Such understanding might provide critical information toward achieving an autonomous oxyfuel-cutting process.