Numerical study of shock wave generated by hydrogen-oxygen detonation in a large shock tube

Blast wave damage and protection experiments conducted in large-scale shock tubes can avoid the inaccurate experimental results caused by the size effect in small-scale model experiments. However, due to the scarcity of equipment, there is still a lack of research on directly simulating the shock waveforms of explosive explosions using large-scale shock tubes at present. Therefore, a numerical simulation study of the generation and propagation process of shock wave generated by hydrogen-oxygen detonation in a large shock tube were conducted, and the reproduction of blast wave in a large shock tube was realized based on numerical simulation. Based on the designs of existing large shock tubes, a two-dimensional axisymmetric model of a large shock tube with driving tube, shock shaping section and variable angle outlet was established. The governing equation of a two-dimensional unsteady viscous compressible flow together with the seven-step reaction of the hydrogen-oxygen detonation mechanism was used to simulate the generation and propagation process of the shock wave. The renormalization group k-ε model was selected as the turbulence model, and the two-dimensional transient coupling solver was used for numerical simulation. Due to the large scale of the model, turbulence has little effect on the far-field shock wave. Therefore, the finite rate component transport model was selected to couple the interaction between turbulence and chemical reaction, and a two-dimensional transient coupled solver was used. Based on the numerical results, the influence of initial physical conditions of the driving gas, inert gas mixing, and the shock tube configurations on the formation of shock wave waveforms by detonation was studied. The variation laws of shock wave characteristic parameters under various factors were summarized. Finally, using the experimental data of black powder explosion shock waves as the target, the process of shock wave waveform regulation in the large shock tube was simulated according to the shock wave variation laws. The results show that under the combined effect of multiple factors, it is possible to simulate and reproduce the specific explosion shock wave using the hydrogen-oxygen detonation driving method in the large shock tube.