Hydrogen is recognized as a most dangerous gas due to high ignition rate and flame speed. In this work, numerical simulations have been performed to simulate the flow pattern and flame deflagration of hydrogen gas inside a confined chamber with different obstacles. This study tries to disclose the transient progress of flame to define the key actual factors affecting flow feature and flame propagation. In order to simulate hydrogen flame deflagration the limited obstacle channel, a three-dimensional model is established and large eddy simulation (LES) method is applied for the simulation of the model. The impacts of obstacle geometry on the pressure distribution are carefully examined. Obtained results show that overpressure inside the confined channel significantly increase within 0.3-0.6 ms. In this work, comprehensive reliable correlation for prediction of the pressure inside the confined channel is present. Our findings clearly demonstrates that velocity-density coefficient plays significant role the pressure distribution inside the model. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.