A Numerical Investigation with Experimental Test of Combined Porous-Free Flame Burner and Its Comparison with a Porous Burner

Premixed combustion in a Combined Porous-Free Flame Burner (CPFFB) and a porous burner (PB) is numerically studied at a cylindrical axisymmetric combustion chamber. The cylindrical porous medium is perforated in the center line that a combination of porous burner and free flame is made. Governing equations of mass, momentum, energy and species mass fraction are solved using finite volume method. In this numerical simulation, a reduced multi-step combustion mechanism and realizable k-ε turbulence model are used. To validate the numerical results, an experimental prototype of the burner was made and has been tested. The numerical results have a good agreement with the experimental data. The results are compared for both types of the burners.The results show that the flame in CPFFB is stable in a range greater than that of PB. The results show that the CPFFB has a higher thermal power about 50% and lower NO pollutant formation about 20% rather than an equivalent PB.