Lifted Turbulent Jet Flames: A Stability Criterion Based on the Jet Large-Scale Structure.

摘要

A model has been developed to predict liftoff heights of turbulent jet flames. This model is based on the large-scale dynamics of the jet flow field and results in a linear relation between liftoff height and jet exit velocity, a relation that has been observed experimentally in prior studies. The parameterization of the liftoff height relation suggested a series of diluted fuel liftoff experiments which were carried out to further test the model. For small dilutions, good agreement between liftoff data and the model's predictions was obtained. For larger dilutions, a systematic deviation from the model was observed, which is not completely understood. The experimentally observed fluctuations in the liftoff height, in conjunction with the agreement achieved with the present model, provide strong evidence that large-scale dynamics determine the stabilization condition in turbulent jet flames. Jet flames; Combustion stability. Reprints. (jes)