In gas explosions, the initial laminar flame transitions to turbulence due to flame-obstacle interactions. Performing large eddy simulation (LES) of gas explosions requires modeling of combustion rate to consider flame wrinkling at the sub-grid scale (SGS). In this study, two SGS combustion models by Charlette et al. (Combust. Flame, 2002) and Colin et al. (Phys. Fluids, 2000) are implemented and assessed in XiFoam. XiFoam is a premixed turbulent combustion solver based on the flame surface density (FSD) approach. The models are validated against experiments described by Patel et al. (Proc. Combust. Inst, 2002). Three obstacles at equal pitch separation are mounted inside a combustion chamber and it is charged with the methane-air mixture at a stoichiometric ratio. Both models capture the increase and decrease in the flame speed as a result of flame-obstacle interaction. However, the model of Colin et al. slightly overestimates the flame speed. The predicted peak overpressures closely match the experimental results. Nevertheless, the arrival of the peak overpressure is better captured by the model of Charlette et al.