Thermal and combustion performance of micro-burner under adiabatic conditions

Author(s)

Dias, D. M. ; Resende, P. R. ; Afonso, A. M.

• Document type: Journal article
• Source: APPLIED THERMAL ENGINEERING; v. 267, p. 11-pg., 2025-05-15.

Abstract

In this work we access the thermal performance and flame dynamics of micro-combustion in a wavy micro- channel using premixed of Hydrogen/Air mixture. This work extends previous works which impose a fixed thermal profile along the wall by exploring the effect of using high insulated wall materials for the micro- combustion chamber and the interaction between the flow dynamics and the combustion reaction, with the aim of understanding in detail the dynamics/stability of the flame in order to improve the efficiency of micro-combustors. The results obtained for different inlet velocities and equivalence ratios, confirmed that the interplay between fluid dynamics and combustion response played a significant role, particularly due to the vortical dynamics generated due to the nonlinear geometry of the burner. For all equivalence ratios the effect of using adiabatic material indicate that at lower inlet velocities, the flame remained stable, whereas at higher inlet velocities, the flame undergoes an unsteady behaviour known as pulsating burst dynamics. A detailed characterization of this pulsating burst dynamics allowed the identification of different stages and access the effect on the thermal and combustion performance using the time evolution for the temperature, velocity, and heat release rate evolve during each of these stages. (AU)

• FAPESP's process: 15/26842-3 - Numerical studies on micro-combustion
• Grantee: Pedro Miguel Rebelo Resende
• Support Opportunities: Scholarships abroad - Research