25.03.2026 - 12:41:55

The Role of Oxide Layer Thickness in Turbulent Iron Combustion

In a study recently accepted for the International Symposium on Combustion, Parsa Ghofrani examines the ignition dynamics of iron particle clouds. High-fidelity simulations reveal that the “rust,” or oxide layer, forming on iron particles acts as a critical barrier to efficient combustion and reliable ignition. As particles are heated within a turbulent flow, this oxide layer continues to grow; when heating is too slow, the layer thickens and significantly impedes ignition.

As a result, the required ignition temperature can rise above the surrounding gas temperature, effectively “smothering” the particles and preventing flame formation. One possible approach to overcome this is preheating. This enables the particles to ignite before the oxide layer becomes prohibitive, allowing a self-sustaining flame to develop. Understanding these microscopic mechanisms is key to designing next-generation, carbon-free industrial burners based on metal fuels.