The LES model based on the progress variable equation and the gradient method to simulate propagation of the reaction front within the detonation wave, which was recently verified by the ZND theory, is tested in this study against two large-scale experiments in the RUT facility. The facility was 27.6 m × 6.3 m × 6.55 m compartment with complex three-dimensional geometry. Experiments with 20% and 25.5% hydrogen–air mixture and different location of direct detonation initiation were simulated. Sensitivity of 3D simulations to control volume size and type were tested and found to be stringent compared to the planar detonation case. The maximum simulated pressure peak was found to be lower than the theoretical von Neumann spike value for the planar detonation and larger than the Chapman–Jouguet pressure thus indicating that it is more challenging to keep numerical reaction zone behind a leading front of numerical shock for curved fronts with large control volumes. The simulations demonstrated agreement with the experimental data.