Three-Dimensional Numerical Simulations to Extend the Measurement Range of Laminar Burning Velocity of Heat Flux Burners

In this work, three-dimensional computational technique is adopted to predict the behavior of flames stabilized over the heat flux burner. The reactive fluid dynamics simulations were performed with ANSYS Fluent®. The configuration of the burner, with prime focus on effect of porosity, is altered to visualize its effect on the flatness of the flames developed over the heat flux burner. The results indicated that, to stabilize wrinkle-free flat stoichiometric flames over the top of burner plate, the burner with high porosity (0.51) is superior to baseline burner with low porosity (0.46). In addition, increased porosity also makes the burner more sensitive for unburnt gas mixtures passing through them. This was verified through parameters like reaction rates and stand-off distances. Furthermore, with an increase in burner plate porosity (reduced solid area) from 0.46 to 0.51, the flame appears closer to the top surface of burner plate to ensure the heat loss required for its stabilization. Due to this, the decomposition of CH₄ and peak of CH₃ come closer to the top surface of the burner plate.