Diffusion Combustion of Hydrogen in a Microjet Outflowing from a Curvilinear Channel

Abstract

In this paper, we examine the combustion of a hydrogen microjet outflowing from a curved channel with a round micronozzle. Jet flows that are generated using rectilinear and curved channels differ in that, in the second case, Dean vortices make a noticeable contribution to the formation of the jet and its combustion. The interaction of the latter with Kelvin–Helmholtz vortices, the formation of which is typical for flows with a velocity shift, causes changes in the combustion characteristics. They include spatial distortions of the laminar flame zone near the nozzle exit, the area of turbulent combustion downstream, as well as the turbulent flame under the conditions of its separation from the nozzle exit and the cessation of laminar combustion in the initial section of the flow. The results of these studies provide the possibility to understand better the combustion features of hydrogen microjets under conditions of their hydrodynamic instability.