Evaluation of the ADREA-HF CFD Code Against a Hydrogen Deflagration in a Tunnel

In the present work, the capabilities of the computational fluid dynamics (CFD) code ADREA-HF to predict deflagration in homogenous, near stoichiometric hydrogen-air mixture in a model of a tunnel were tested. The tunnel is 78.5 m long. Hydrogen-air mixture is located in a 10 m long region in the middle of the tunnel. Two cases are studied: one with a complete empty tunnel and one with the presence of four vehicles near the center of the tunnel. The combustion model is based on the turbulent flame speed concept. The turbulent flame speed is a modification of Yakhot's equation, in order to account for additional physical mechanisms. A sensitivity analysis for the  parameter of the combustion model and for the mesh resolution was made for the empty tunnel case. The agreement between experimental and computational results concerning the value of the maximum pressure, and the time it appears, is satisfactory in both cases. The sensitivity analysis for the parameter of the combustion model showed that even small changes in it can have impact on the simulating results, whereas the sensitivity analysis of the mesh resolution did not reveal any significant differences.