Three-dimensional numerical simulation of the operation process in a continuous detonation combustor with separate feeding of hydrogen and air

To verify the predictability of a computational technology developed at the Semenov Institute of Chemical Physics, Russian Academy of Sciences, three-dimensional calculations of the operation process in a hydrogen-air continuous detonation combustor (CDC) of the Lavrent'ev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences have been conducted with the reproduction of the geometrical dimensions of all the elements of the experimental combustor and the main operating conditions. The calculation results are in good agreement with the experiment data on all the measured characteristics. The problem of the applicability of a planar two-dimensional approximation with periodic boundary conditions to the simulation of the physicochemical processes in an annular CDC has been specifically studied. It has been shown that the distributions of density, temperature, Mach number, and axial velocity component in the different sections of the combustor are substantially three-dimensional, whereas the static pressure distribution approaches a two-dimensional pattern with increasing distance from the bottom of the CDC. The three-dimensional calculations have shown that the conventional assumption of a supersonic discharge at the outlet of a two-dimensional computational domain is not always correct: extensive zones of a subsonic discharge of detonation products can exist in the outlet section.