Effect of Obstructed Space on the Parameters of Shock Waves from the Deflagration of Hydrogen-Air Clouds

This article considers the generation of pressure waves during the combustion of hydrogen-air clouds in various modes. The problem of the combustion of spherical clouds, in which the inner spherical volume burns with an apparent velocity of 240 m/s, and the remaining outer layer with an apparent velocity of 100 m/s, is considered. Also, for comparison, two limiting cases are considered: the combustion of the entire cloud with constant velocities of 100 and 240 m/s. The problem is solved numerically in a one-dimensional formulation, with the combustion front clearly identified. As a result, using precise numerical simulation, it is shown that the deflagration of secondary volumes of hydrogen-air mixtures in an open space at a slow speed (up to 100 m/s) does not lead to an increase in pressure in the waves generated earlier during the deflagration of the primary volume at a fast speed corresponding to deflagration in an obstructed space. Such a situation is observed for the inner region of various sizes (the portion of the cloud that burns at a high rate).