Validation of CFD predictions of gas explosions

A variety of experiments have been carried out in order to validate computational fluid dynamics (CFD)-based models for predicting overpressures caused by gas explosions. Two experimental rigs have been developed, enabling pressures to be measured in both confined and semi-confined volumes during explosions of either methane or propane in air. In addition to measurements of pressures, high-speed video has been used to study the movement of the flame front and the development of turbulence during vented gas explosions. The results show how turbulence develops rapidly as the flame progresses around obstacles, with the scenario causing the most rapid development of turbulence and acceleration of the flame also generating the maximum pressure. Comparison with predictions made using CFD models highlight the difficulty in accurately modelling realistic explosion scenarios. In addition, it is evident that the K−e model used for turbulence needs to be improved or replaced by one more suitable for fast swirling flows if CFD models are to be used to predict explosion overpressures