Pressure profiles in detonation cells with rectangular and diagonal structures

Experimental results presented in this work enable us to classify the three -dimensional structure of the detonation into two fundamental types: a rect angular structure and a diagonal structure. The rectangular structure is we ll documented in the literature and consists of orthogonal waves travelling independently front each another. The soot record in this case shows the c lassical diamond detonation cell exhibiting 'slapping waves'. The experimen ts indicate that the diagonal structure is a structure with the triple poin t intersections moving along the diagonal line of the tube cross section. T he axes of the transverse waves are canted at 45 degrees to the wall, accou nting for the lack of slapping waves. It is possible to reproduce these dia gonal structures by appropriately controlling the experimental ignition pro cedure. The characteristics of the diagonal structure show some similaritie s with detonation structure in round tube. Pressure measurements recorded a long the central axis of the cellular structure show a series of pressure p eaks, depending on the type of structure and the position inside the detona tion cell. Pressure profiles measured for the whole length of the two types of detonation cells show that the intensity of the shock front is higher a nd the length of the detonation cell is shorter for the diagonal structures .