Work

Study on combustion performances of partially premixed flame in a micro-combustor with cavity

Year: 2025

Type: article

Abstract: Combustion characteristics of a partially premixed flame in a micro-combustor with a wall cavity were studied numerically under various primary air coefficient conditions (α = 0.35, 0.5, and 0.65). The results show that the cavity has a significant effect on flame structure, a typical double-flame structure was observed (namely, a trapped-vortex flame and a main flame). Although the trapped-vortex flame is relatively weak, it is of importance to the stability of the main flame through heat recirculation mechanisms. The cavity has a strong ability to effectively extend the operating range of inlet velocity (Vin) at a higher primary air coefficient. Furthermore, the effects of inlet velocity and primary air coefficient on the double-flame structure were investigated. It was found that with the increase of inlet velocity, the area of reaction zone, temperature, and heat release rate (HRR) of both the trapped-vortex flame and the main flame are increased simultaneously. An increase in the primary air coefficient results in a larger reaction zone, higher temperature, and HRR for the trapped-vortex flame, while those for the main flame are opposite. According to the field synergy principle, we noted that a higher inlet velocity does not necessarily lead to a better preheating effect of the fresh mixture. Moreover, a dimensionless number, Eu, defined as the ratio of the pressure difference (ΔP) between the inlet and exit of the burner to the dynamic head of the inlet jet flow, is introduced to evaluate flow resistance. The Eu number decreases with the increase of inlet velocity, but exhibits an opposite trend with primary air coefficient.

Source: Case Studies in Thermal Engineering

DOI: 10.1016/j.csite.2025.107517

Authors: Fangfang Zhang, Xiaoting Xu, Pengyuan Zhang, Xinjie Huang, Jing Li, Yinhu Kang

Institutions: Anhui University of Technology, Chongqing University

Language: English

Topic: Combustion and flame dynamics

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,620

Funders: National Natural Science Foundation of China, China Postdoctoral Science Foundation