  Pulverized iron flames stabilized in a multidimensional hot counterflow
burner are simulated using a numerical model, which is extended from the
state-of-the-art model developed by Hazenberg and van Oijen (PCI, 2021)
considering unsteady effects. The results are compared to available
experimental data (McRae et al., PCI, 2019), including particle image
velocimetry measurements, a direct flame photo, the flow field velocity and the
flame speed for different iron and oxygen concentrations. The comparison shows
that the particle dynamics and flame shape can be reasonably well predicted.
The flow field velocity and flame speed also show quantitative agreement
between the simulation and the experiment. Based on the validated simulation
results, the iron combustion characteristics, including the thermal structures
and the multidimensional effects, are analyzed for different oxidizer
environments. The analysis shows that the iron particles undergo a transition
from kinetic-controlled regime (up to ignition) to a diffusion-controlled
regime (burning) at the central axis for both environments with the particle
temperature being higher than the gas temperature at the flame front, which is
indicated by the Damk\"ohler number. For the hot counterflow burner, there
exist multidimensional effects, i.e., the temperature and Damk\"ohler number
change along the radial direction.
