Title: Characteristics and soot formation in laminar liquefied petroleum gas flames in air crossflow
Authors: S. Muthu Kumaran; Vasudevan Raghavan
Addresses: Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai – 600036, Tamil Nadu, India ' Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai – 600036, Tamil Nadu, India
Abstract: Crossflow non-premixed LPG-air flames display stability issues at higher air velocities. They also emit notable amount of soot. To improve the flame stability, obstacles such as backward facing steps, are used. In this work, laminar LPG-air crossflow flames are studied using a comprehensive numerical model incorporating multi-component mass transfer with thermal diffusion, diffusion energy source, sub-models for soot formation, its oxidation and radiation losses due to gas and soot. For the cases without backward facing step (baseline cases), the flame is unstable after a given air velocity. Flames are much stable over an increased air velocity, when a backward facing step is used. In these cases, the net soot production is relatively higher when compared to baseline cases as a result of increased residence time in the wake of the step. The location of the step from the fuel injection point also has its effects on soot formation.
Keywords: backward facing step; multi-component mass transfer; soot formation; gas radiation; soot radiation; numerical model; kinetic mechanism; crossflow; liquefied petroleum gas; LPG.
Progress in Computational Fluid Dynamics, An International Journal, 2021 Vol.21 No.5, pp.305 - 315
Received: 24 Jun 2020
Accepted: 01 Oct 2020
Published online: 15 Jul 2021 *