The effect of venting structures on overpressure caused by an indoor explosion

Introduction. The article considers an accidental indoor gas explosion on condition of pressure relief through openings in which venting structures were installed. A solution to this problem can protect residential buildings from consequences of explosions due to the fact that the volume of premises in residential buildings is small compared to industrial buildings, and it determines more stringent pressure relief conditions at the initial moment of the explosion development. The article shows that pressure can reach critical values in a small space during the motion of a venting structure in the opening before the onset of pressure relief. Goals. The authors aim to identify the pattern of blast load development from the moment of explosion to the attainment of the maximum pressure value with account taken of the properties of venting structures and patterns of their opening. This goal is relevant due to the fact that until now at this stage pressure development has been considered without any account taken of how deeply the venting structure is installed in the wall opening. Much attention was focused on the selection of the opening size. Methods. The methods of the theory of dimensions, numerical and analytical modeling of explosion processes, patterns of gas escape and rigid body motion were applied to obtain dimensionless groups describing the development of an explosive load until maximum values. These dimensionless groups allow identifying explosive loads for rooms having different volumes, which is also a new result. Results. In this work, the influence of individual factors on the ultimate result has been identified. These factors are the room volume, the pressure at which the venting structure starts moving, the mass and position of the venting structure in the opening, the opening perimeter and the rate of explosive combustion. Conclusions. The results, obtained in the course of this work, allow identifying the dynamic load of an explosion at the stage of its growth. This value can be used to set more reliable bearing characteristics of structures for cases of accidental explosions in living accommodations.