Work

Effect of Additively Manufactured Wall Lattice Structures on Flashback Limits in a Hydrogen Jet Flame Combustor

Year: 2026

Type: article

Abstract: This study investigated how additively manufactured nozzles with body-centered cubic lattice structures reduce the flame flashback propensity in a hydrogen jet flame burner. Five different configurations of a jet flame combustor were investigated, with a focus on mixing duct walls incorporating porous media. The nozzles were manufactured by the powder bed fusion of metals using a laser beam process. The lattice parameters were varied by the volume fraction and the strut diameter. For the experiments, pure hydrogen was used as fuel under atmospheric conditions at various equivalence ratios and Reynolds numbers of 9000–12,000. Flow field measurements, flame imaging, and spectral proper orthogonal decomposition of the flame dynamics were employed to identify possible transition mechanisms from a stable operation to flashback. The flow fields and the flame shapes showed only minor effects from wall modifications, preserving general flow characteristics across configurations. The flow dynamics in the combustion chamber were dominated by large-scale coherent structures in the shear layer, specifically Kelvin-Helmholtz instabilities. The results demonstrated that the nozzle with the coarsest porous wall structure significantly improved the flashback resistance compared to a nozzle with a solid wall. It is concluded that the primary mitigation mechanism was a cooling effect by unburnt mixture flowing through the porous media. The findings confirmed that the integration of lattice structures through additive manufacturing provides a viable strategy for hydrogen flashback mitigation by manipulating the coupled interaction between the flame and the thermal conditions of the wall.

Source: Journal of Engineering for Gas Turbines and Power

DOI: 10.1115/1.4072619

Authors: Alexander Jaeschke, Thomas Ludwig Kaiser, Lukas Melzig, Michael F. Zaeh, Kilian Oberleithner, Christian Oliver Paschereit

Institutions: Technische Universität Berlin, Technical University of Munich

Language: English

Topic: Combustion and flame dynamics

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Funder: Deutsche Forschungsgemeinschaft

Awards: ENERGIZE: Adjungiertenbasierte Optimierung von WasserstoffBrennern mithilfe additiver Fertigung, G6595915919, Verbesserung der reaktiven Mittelfeldanalyse von industriellen Brennergeometrien durch maschinelles Lernen zur Optimierung der Umwandlung von grünem Wasserstoff in elektrische Energie