Analysis of Lift off Height and Blow-Off Mechanism of Turbulent Flame by V-Gutter Bluff Body

Abstract

The experimental investigation has been carried out to study the stabilization and blowout mechanisms of turbulent flame stabilized by V-gutter bluff body in a square duct at reactive and non-reactive conditions. V-shaped bluff bodies made of stainless steel having 1.6 mm thicknessare used for stabilization of the flame.Experiments have been conducted at selective velocities of commercially available methane and oxygen with 60 degree V-gutter as flame holder. It is observed that at stoichiometric conditions, the V-gutter is dominated by shear layer stabilized flames. The flame stability is influenced by bluff body dimensions and mass flow rate which play a major role in combustion instabilities mixing of air fuel ratio and blow off. The lift off decreases at higher blockage ratios.A strong recirculation zone is found in this test rig immediately downstream of the V-Gutter which gradually subsides and disappears far downstream.The lift off height is not much affected by the velocity of the fuel-air mixture.