Experimental study of stability of V-shaped flame in a premixed swirl burner

In this work, stability of V shaped flame in a premixed swirl burner is studied. The effect of firing rate (input energy per unit area), equivalence ratio and axial velocity of fuel and air mixture on the stability of a V shaped flame is studied. For swirl generation, a 45o angle swirler is used in the air inlet, which yields a flow with a swirl number of 0.78. Observations show that V shaped flame is formed in a lean mixture of fuel and air (1> fi) . When firing rate increases, it is observed that flow velocity at V flame formation instant is independent of flow rate and increases linearly from 1 m/s to 5 m/s. flame lift off occurs in larger equivalence ratio and mixture velocity when firing rate increases. With increasing mixture velocity, flame quenching occurs in smaller equivalence ratios and larger firing rates. Hence, stability limit of V flame increases with increasing cross section.