Journal of Applied Mechanical Engineering

Stable detonative combustion of hydrogen in a supersonic flow coming in a convergent - divergent nozzle

2^nd International Conference on Fluid Dynamics & Aerodynamics

October 19-20, 2017 | Rome, Italy

Yuri V Tunik

Research Institute for Mechanics of MSU, Russia

Keynote: J Appl Mech Eng

Abstract:

The possibility of stationary detonation combustion of hydrogen-air mixture coming into an axisymmetric convergentdivergent nozzle with a high supersonic velocity is investigated. A necessary condition for the stabilization is the formation of supersonic flow in the convergent section of the nozzle Therefore first, this work experimentally and numerically solves the problem of the starting of a convergent - divergent nozzle in a supersonic flow. It is shown that the supersonic start-up can be realized both by throwing a nozzle into the formed supersonic stream, and when the nozzle is accelerated to a given velocity. A peculiarity of the flow formed is the emergence of an oblique shock wave in the convergent section of the nozzle and the Mach disk because of this wave interaction with the axis of symmetry. In calculations with combustion, air at the inlet to the nozzle is replaced by a hydrogen-air mixture of a given concentration. The main difficulty in the problem of stabilization of detonative combustion is associated with the spontaneous ignition of hydrogen behind the Mach disk and the propagation of detonation upstream. Additional problems arise when initiating detonative combustion of hydrogen under conditions of a rarefied atmosphere: the ignition does not guarantee the formation of a stationary detonation in the nozzle. Investigations are fulfilled on the base of Euler gas dynamics equations with detailed kinetics of combustion. Calculations are made use modified Godunovâ??method. It is shown the possibility of stabilizing the detonative combustion of hydrogen-air mixtures coming into the axisymmetric nozzle at the Mach number from 7 to 9 at heights up to 16 km.

Biography :

Yuri V Tunik graduated from a usual school in the small town of Moscow region and entered the Mechanical Mathematics Department of Moscow State University by name M V Lomonosov (MSU). In 1970, he received higher education and continued to study at the graduate school of the same faculty. In 1976, he defended his thesis on gas-dynamic lasers and in 2002, the thesis "Dynamics of combustion in two-phase media containing methane" to acquire scientific degree of the Doctor of Physical and Mathematical Sciences. Since 1974, he has been working as a Researcher in the Research Institute of Mechanics of MSU. Currently he is a leading Researcher.