Gaseous detonation propagating in a coaxial cylinder was studied for hydrogen/oxygen/nitrogen mixtures numerically and experimentally. The numerical method used was based on the three-dimensional Euler equations with detailed finite-rate chemistry. Smoked foil measurement was performed to record the cellular structure of the detonation propagation. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by the continuously rotating detonation is visualized and the distinctive features of the rotating detonations are clearly depicted. Due to the curvature of the annular tube, the size of cellular pattern along the concave wall is smaller than that along the convex wall. This implies that the detonation wave near the concave wall is convergent and therefore is stronger than that near the divergent convex wall. Also, the numerical simulations show three-dimensional rotating detonation structures, where display the special combined detonation. (C) 2011 The Combustion Institute. Published by Elsevier Inc. All rights reserved.