Effects of gradient magnetic field on swirling flame dynamics

The recent research was focused on experimental study and mathematical modelling of the gradient magnetic field effect on the development of swirling flame dynamics to better understand the mechanism of the interaction between the swirling flames and the non-uniform magnetic field and to provide control of the main gasification/combustion characteristics at thermo-chemical conversion of biomass (wood) pellets. The experimental study of the magnetic field influence on the swirling flow dynamics and on the composition of the products was carried out, using an experimental device, which is composed of a gasifler and water-cooled sections of the combustor, downstream of which the swirling flow field develops. The upper part of the gasifier was exposed to a transverse magnetic field. The magnetic field was created by two pairs of permanent magnets, producing a non-uniform, upstream increasing magnetic field with the mean axial magnetic field gradient dB/dz ∼ 0.8-1 T m^-1. The experimental study includes a joint research of the gradient magnetic field effect on the formation of flow velocity, flame composition and temperature profiles as well on the heat output at different stages of biomass thermo-chemical conversion providing analysis of the applicability of the gradient magnetic field for the control of biomass thermal decomposition, combustion of volatiles and heat energy production. The experimental results along with the mathematical modelling and computer simulation using different software confirm the influence of the external magnetic field on the stream, vorticity, temperature and species mass fraction fields indicating more effective burnout of volatiles and cleaner heat energy production.