Features of the Round Hydrogen Microjet Combustion in a Coaxial Jet of the Air and Nanopouder Mixture

Abstract

Results of the experimental studies of a round hydrogen microjet combustion in a coaxinal jet of air and SiO2 nanopouder mixture efflux from a slot-hole (multinozzle) coaxial nozzle at subsonic and supersonic efflux velocity are presented. It is shown that scenarios of a hydrogen microjet combustion in a coaxinal jet of air and nanopouder mix-ture are similar to scenarios of diffusion combustion of a hydrogen microjet at subsonic and supersonic efflux veloci-ty. Existence of “bottleneck flame region” is revealed at subsonic and a flame separation from a nozzle exit at super-sonic efflux velocity. It is found that with efflux velocity growth of jets it is possible to observe intensification of the luminescence of the flame at the boundary between the jet of hydrogen and air / nanopowder mixture and existence of «bottleneck flame region» as in a laminar coaxial jet and in a flame of a hydrogen microjet combustion. On the other hand, it is possible to observe actually disappearance of the «bottleneck flame region» at approach to transonic efflux velocity.