Thursday, February 14, 2013
Mechanical and Civil Engineering Seminar
Highly Turbulent Flames: Another Variation on the Counterflow Theme
Alessandro Gomez, Professor of Mechanical Engineering, Mechanical Engineering and Materials Science, Yale University
I will review ongoing experimental research in my group on turbulent flames in the counterflow configuration. Since the pioneering work of Weinberg's group at Imperial College in the '60s, the counterflow system has been the workhorse of laminar flame studies. Recent developments have shown that it is also a promising benchmark for highly turbulent (Ret ~1000) nonpremixed and premixed flames. Case studies will demonstrate the versatility of the system in mimicking real flame effects such as heat loss and flame stratification in premixed flames and the compactness of the combustion region in nonpremixed flames. The system may offer significant advantages from a computational viewpoint, including: a) aerodynamic flame stabilization near the interface between the two opposed jets, with ensuing simplifications in the prescription of boundary conditions; b) a fiftyfold reduction of the domain of interest as compared to conventional nonpremixed jet flames at the same Reynolds number; and c) millisecond mean residence times, which is particularly useful for DNS/LES computational modeling, and for soot suppression in the combustion of practical fuels.