Seminars and thesis defenses
Harmony in High Speed Combustion
By Powers Joseph (University of Notre Dame (USA))
Processes in nature are often sometimes characterized by disorder and other times by order. Such is the case with the phenomena of combustion; one can compare the disorder of a crackling flame in a fireplace to the order of a candle flame in still air. Analogs exist in high speed combustion such as might be present in rocket nozzles or high speed air-breathing jet engines. Here, a paradigm problem in high speed combustion will be considered in which the transition from order to disorder will be studied in a controlled fashion. The mathematical model is one that closely mimics nature, namely the compressible reactive Navier-Stokes equations for a mixture of calorically imperfect ideal gases that react via a model of detailed chemical kinetics. The key physical mechanisms considered are reaction, advection, and diffusion. Their relative importance dictates the physical flame structures which are predicted. One-dimenensional unsteady models of hydrogen-air combustion are examined.