Toward fundamental improvements to engineering models for gas explosions in complex geometries by utilizing experimental results in conjunction with highly resolved numerical simulations

Abstract Engineering models for gas explosions chiefly rely on porosity/distributed resistance (PDR) technique, where volume and area blockage created by obstacles are primarily taken into account for modeling. However, it is anticipated that other geometric parameters like the number of obstacles and their orientation or location play a crucial role. Toward this end, a computational fluid dynamics (CFD) analysis of vented methane‐air explosions is performed using large eddy simulations (LES). Four different configurations are considered, where the obstacles' volume and area blockage are kept constant, while only altering the obstacles' orientation and position relative to each other. The resulting effects on flame position, flame speed, flame acceleration, and generated overpressure are analyzed. The results show that the configuration that exhibits the highest flame wrinkling and flame surface area among all the configurations leads to the maximum peak overpressure. Although the obstacle volume is the same in all cases, it was striking to observe that a simple reorientation or repositioning of the obstacles can mitigate or aggravate the explosion overpressures by 35% or 253%, respectively. This study highlights that obstacle orientation and pattern are as important as volume blockage and should be considered for PDR modeling.