Numerical Investigation of Flame Propagation in Constant-Volume Premixed Combustor: Effects of Turbulence–Chemistry Interaction and Wall Materials

Abstract

The present numerical investigation on constant-volume premixed kerosene–air combustion using the Species Transport model in ANSYS Fluent to examine how turbulence–chemistry interaction (TCI) modeling and combustor wall thermal properties effect flame spread between two different combustion methods. A two-dimensional combustible material testing system which used an equivalence ratio of 0.8 to operate under fixed constant-volume testing conditions. The study is conducted to predict performance of the Finite Rate (FR) and Finite Rate/Eddy Dissipation (FR/ED) models using different wall materials such as aluminium alloy, carbon–carbon composite, Inconel, and silicon carbide liners. The Finite Rate model underpredicted the realistic flame dynamics which resulted in localized ignition-dominated hot spots and fragmented flame structures and weak turbulence–flame coupling and persistent unburnt fuel regions that demonstrated kinetically limited and incomplete combustion. The FR/ED model succeeded in tracking turbulence-assisted flame propagation as it creates continuous flame fronts with distributed turbulence kinetic energy and nearly complete fuel consumption for all materials. The study found that aluminium alloy flame temperature increased from 2036 K (FR) to 2105 K (FR/ED) at 100 mm from the inlet while maintaining consistent thermal patterns for all liners. The wall lining materials analysis showed that aluminium alloy burned with the fastest flame speed and highest combustion power while carbon–carbon composite maintained stable combustion through its ability to minimize heat loss and Inconel completely prevented flame spread through its capacity to absorb heat and silicon carbide showed performance that fell between the two extremes. The results demonstrate that constant-volume premixed combustion prediction requires both turbulence–chemistry coupling and wall heat-transfer modeling while the FR/ED model provides advanced propulsion and compact combustor systems with better predictive accuracy than the Finite Rate method.