Cellular and Spin Detonation in 3D Channels

Abstract

Gas detonation is a complex multidimensional process. In nature, the multidimensionality of detonation manifests itself in the cellular structure and in the spin. The cellular and spin detonations are formed due to instability of the burning zone behind the head shock wave, due to which small perturbations increase, and periodic spatial flows arise with transverse waves in the flow behind the head shock and with breaks of its front [1, 2]. In this work, we simulated in the 3D unsteady formulation the process of spontaneous formation of the 3D detonation structure observed in experiments and its propagation in the channels of square, rectangular, round, and elliptic cross sections. We investigated in detail the process of spontaneous increase in small perturbations and the transformation of the 1D flow into the flow with the substantially 3D detonation structure, which is called cellular by analogy to the 2D case. In case of circular cross section, we simulated the process of spontaneous formation of spin detonation and investigated stability of spin detonation to disturbances caused by changing diameter of the channel. In all cases the initial distribution of parameters was one-dimensional.