Effects of turbulence intensity and length scale on the flame location of premixed turbulent combustion in a diffuser combustor

Abstract

This study focused on the dependency of the flame location of a premixed propane-air flame on turbulence intensity and length scale. The flame location was investigated using a diffuser-type combustor to show the response of the flame location to varying turbulence intensities and length scales without changing the mixture velocity, i.e., the thermal power. Combustion simulations were conducted using a coherent flame model within the framework of Reynolds-averaged Navier-Stokes equations under unsteady state conditions. The flame generally moved toward the combustor inlet with increases in turbulence intensity and length scale. The combustion and inlet turbulence caused a flow separation mainly downstream of the flame front. Consequently, the secondary flow structures influenced the flame topology and location.