Autor(es)

Fachini, Fernando F. ; Bianchin, Rafael P. ; Severino, Matheus P. ; Sauer, Vinicius M.

• Tipo de documento: Artigo Científico
• Fonte: COMBUSTION SCIENCE AND TECHNOLOGY; v. N/A, p. 15-pg., 2025-12-19.

Resumo

Double Tsuji flames represent a fundamental combustion configuration where a cylindrical porous burner is positioned at the center of two identical planar oxidizer opposed-flow jets. Despite its simplicity, solving the associated complex governing equations representing the system requires extensive treatment for a detailed flame description. Scale analysis offers an alternative to a complete solution by identifying the most significant processes at different scales to better understand the behavior of the system. The scale analysis of double Tsuji diffusion flames assumes three hypotheses: I - the fuel flux from the cylindrical burner is redirected toward the major axis of an ellipse, where it is consumed by the flame located along the perimeter of the ellipse, II - a fuel fluid particle traveling along the major axis of the ellipse encounters an oxidizer fluid particle that traverses a distance equal to the minor axis at diffusion speed, and III - the flow field is potential. While this simplification may not capture every detail of the system, potential flow provides an effective approximation that complements the species conservation model. Moreover, although thermal expansion effects are not explicitly accounted for in the flow, they are integrated into species conservation. The analysis reveals a parameter that properly merges the stoichiometric air-to-fuel ratio, flame temperature, P & eacute;clet numbers based on the fuel and oxidizer flows, and a geometric factor. That parameter describes the problem geometry compactly, confirming the hypotheses and providing a proper understanding of the problem. The scale analysis is validated with experimental results. A key feature of the model is the division of the flame into two geometric regions: a cylindrical segment near the burner and an elliptical segment downstream. The transition between these regions defines an angle, which is adjusted to match the theoretical flame length with experimental observations. (AU)

• Processo FAPESP: 21/09246-9 - Uma nova configuração de combustão com controle externo do arrasto de oxidante
• Beneficiário: Fernando Fachini Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 21/10689-2 - Acoplamento entre instabilidades hidrodinâmicas e chamas difusivas com mudança drástica de forma e sob ação do empuxo
• Beneficiário: Matheus de Padua Severino
• Modalidade de apoio: Bolsas no Brasil - Doutorado