On the Efficiency of Blast Relief Panels Located in the Cover

The dynamics of the development of an internal explosion is studied considering the action of blast relief panels. The time spent on the exit of the blast relief panel from the opening, as well as the effect of gravity, are considered. The processes are investigated from the moment the blast relief panel leaves the opening and until it is fully opened. A model is formed considering the initial speed of the blast relief panel at the exit from the opening. The model is limited to considering the pressures, at which it is assumed that the degree of expansion of gases during combustion is unchanged, and to determine the rate of gas outflow, the Bernoulli equation for an incompressible liquid is applicable. Dimensionless complexes and parameters characterizing the process under study are established. As a final result, the dependence of the maximum pressure during the opening-up of the opening (the first peak) from the dimensionless complex based on the initial data is proposed. Among them are the characteristics of the blast relief panel, the combustion rate, the geometric shape, and dimensions of the opening. It is concluded that the maximum possible pressure at the first peak does not directly depend on the area of the opening. The rate of pressure relief at the moment of opening-up of the opening is determined by the area of the side space calculated as the product of the perimeter of the opening to the amount of displacement of the blast relief panel. A method is proposed for reducing pressure at the first peak by increasing the number of openings while maintaining the total area for pressure relief, which depends on the bearing capacity of panels. The results obtained allow to establish under what conditions the pressure at the first peak exceeds the pressure at the second one. Thanks to this, it is possible to adjust the explosion resistance of an object by changing the design of a blast relief panel, or by strengthening the load-bearing elements.