Combustion Characteristics of Premixed Hydrogen/Air in an Undulate Microchannel

Autor(es)

Resende, Pedro R. ^{[1, 2]} ; Morais, Leandro C. ^[3] ; Pinho, Carlos ^[1] ; Afonso, Alexandre M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Porto, Dept Mech Engn, CEFT, P-4200465 Porto - Portugal

^[2] Inst Politecn Viana Do Castelo, Escola Super Tecnol & Gestao, proMetheus, P-4900347 Viana Do Castelo - Portugal

^[3] Sao Paulo State Univ Unesp, Inst Sci & Technol, BR-18087180 Sorocaba - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENERGIES; v. 15, n. 2 JAN 2022.
• Citações Web of Science: 0

Resumo

This work reports a numerical investigation of microcombustion in an undulate microchannel, using premixed hydrogen and air to understand the effect of the burner design on the flamein order to obtain stability of the flame. The simulations were performed for a fixed equivalenceratio and a hyperbolic temperature profile imposed at the microchannel walls in order to mimic theheat external losses occurred in experimental setups. Due to the complexity of the flow dynamicscombined with the combustion behavior, the present study focuses on understanding the effect of thefuel inlet rate on the flame characteristics, keeping other parameters constant. The results presentedstable flame structure regardless of the inlet velocity for this type of design, meaning that a significantreduction in the heat flux losses through the walls occurred, allowing the design of new simplersystems. The increase in inlet velocity increased the flame extension, with the flame being stretchedalong the microchannel. For higher velocities, flame separation was observed, with two detecteddifferent combustion zones, and the temperature profiles along the burner centerline presented anon-monotonic decrease due to the dynamics of the vortices observed in the convex regions of theundulated geometry walls. The geometry effects on the flame structure, flow field, thermal evolutionand species distribution for different inlet velocities are reported and discussed. (AU)

• Processo FAPESP: 15/26842-3 - Estudos numéricos em micro-combustão
• Beneficiário: Pedro Miguel Rebelo Resende
• Modalidade de apoio: Bolsas no Exterior - Pesquisa