Detailed structure of spinning detonation in a circular tube

A single spinning detonation wave propagating in a circular tube, discovered experimentally in 1926, is simulated three-dimensionally with a detailed chemical reaction mechanism. The detonation front obtained numerically rotates periodically with a Mach leg, whiskers, and a transverse detonation. A long pressure trail, which is distributed from the transverse detonation to downstream, was reproduced, clearly showing that the pressure trail also spins synchronously with the transverse detonation. The formation of an unburned gas pocket behind the detonation front was not observed in the present simulations because the rotating transverse detonation completely consumed the unburned gas. The calculated profiles of instantaneous OH mass fraction have a keystone shape behind the detonation front. The numerical results for pitch, track angle, Mach stem angle, and incident shock angle on the tube wall agree well with the experimental results.