Computational and Experimental Investigation of Turbulent Nonpremixed Cool Flames

Nonpremixed cool flames have received increasing attention recently due to their importance in real combustion devices, such as diesel engines, where cool flames are often present alongside hot flames in turbulent flows. One way to learn about the fundamental physics behind turbulent nonpremixed cool flames in real systems is to first study them in isolation, free from the effects of any neighboring hot flames. To date, such studies have been strictly computational, due to the difficulty of isolating a turbulent cool flame experimentally. Recently, a new Co-flow Axisymmetric Reactor-Assisted Turbulent (CARAT) burner has been developed that is capable of experimentally studying isolated turbulent cool flames in a statistically stationary jet configuration.  In this work, an isolated nonpremixed turbulent cool flame of dimethyl ether is computed in the same configuration using Direct Numerical Simulation and compared to experimental measurements of temperature and formaldehyde.  The comparisons provide further insights into the fundamental structure of turbulent nonpremixed cool flames.