Numerical study of 3D gaseous detonations in a square channel

Abstract

The multidimensional structure of mildly unstable detonations are examined by numerical computations. These phenomenon have grown in interest since the development of propulsion devices such as pulsed and rotating detonation engines. Rectangular, diagonal and spinning modes are observed in a near-limit propagation detonation. High-order numerical integration of the reactive Euler equations have been performed to analyze the averaged structure, the shock dynamics of a single-cell detonation propagating in a square channel. Computations show a good agreement with the experimental cellular structure, showing the relevance of the slapping waves in the rectangular modes. The hydrodynamic thickness as well as the pdf shock dynamics are similar in the 2D and 3D cases, but the mean quantities vary on a quantitative basis. Moreover, the presence of strong forward jets is attested, which comes from simultaneous triple point line collisions with the walls.