Observations of the Structure of Spinning Detonation

Spinning detonation waves in acetylene‐oxygen mixtures highly diluted with argon have been studied in circular tubes by a variety of simple photographic, electrical, and mechanical (soot inscription) techniques. The combined results of these experiments permit the deduction of a fairly detailed description of the system of shock waves, reaction zones, and contact zones which exists at the front of the spinning detonation. The outstanding feature of the observed structure is that about half of the gas near the tube wall is burned in a wave which propagates in a nearly circumferential direction through shocked, unburned gas behind the nonplanar primary shock front. The relation of this structure to that of White's ``laminar detonations'' in rectangular nozzles and to spinning detonation wave structures recently proposed by certain Russian workers is discussed.