On the effect of repulsive magnetic field on partially premixed flames

Abstract

Abstract The premixed flames are important with wide range of applications from burners, gas turbine combustor, mixing studies to practical, functional, engineering and scientific research applications. One of the interesting cases of premixed flames is partially premixed flames which has redirected the attention of the scientific community. The partially premixed flames represent incomplete burning, safety hazards, heterogeneous heat and mass transfer. The flame stability of premixed flames comprises an integral role in most of the propulsion applications. For efficient combustion operations and applications, flame stability is mandatory and different approaches have been tried. However, the complexity of the problem has prevented a thorough understanding. One aspect of transitional energy interaction which is yet to be tried is the interaction of magnetic energy with the thermal energy in partially premixed flames. The energy interactions are likely to alter the high energy field supporting flame stabilization and control. The major application includes, enhancement of fundamental understanding and optimization of potential gas turbine combustors, spacecrafts and magnetic nozzles etc. Thorough experimental investigation was carried out utilizing Bunsen burner and designated magnets for varying number of external energy sources, continual variation in interspace distances, and different configurations in repulsion fields. The magnetic effect on the flames is characterized in terms of geometric flame classification viz., Blue flame length (BFL), Yellow flame length (YFL) and Gross flame length (GFL) along with the visible structural changes in the flames. Results clearly state that presence of magnetic energy in the immediate vicinity significantly affect the flame behaviour. With systematic reduction in the separation distance, a non-monotonous drop in the BFL is observed for the cases of 2,3,4 magnet configuration(s) with reduction in the interspace distance.