Positional Relation of Flame and Vortex Filament Soliton in High-Speed Flame Propagation along a Vortex

Abstract

The unsteady 3-D numerical simulation was carried out in order to clarify the relative locations of flame and vortex filament soliton in the high-speed flame propagation phenomenon (the vortex bursting) along a line vortex. The position of vortex filament soliton was determined by a peak point of curvature distribution along the vortex line. The position of flame was determined by 3 kinds of physical properties, respectively; a gradient region of temperature distribution, a peak point of temperature gradient distribution, and a peak point of heat release rate distribution along the vortex line. In the 1-D analysis of flame propagation speed and in the 3-D visualization of helical vortex lines around the flame top, it was confirmed that the vortex bursting occurred in this numerical simulation. Furthermore, in the 1-D analyses of vortex line curvature, temperature, temperature gradient, and heat release rate along the vortex line, the peaks of vortex line curvature (the vortex filament solitons) were observed at the same locations as the peaks of temperature gradient and heat release rate (the flames), and the flames and the vortex filament solitons propagated in pairs along the vortex line. Due to these results, an evidence to support the vortex driving mechanism (the interaction between flame and vortex filament soliton) in the vortex bursting was obtained.