Liquid Film Cooling Using Swirl in Rocket Combustors

*† ‡ Liquid film cooling is an important method to maintain structural integrity of rocket combustor walls. Studies available in the open literature are mostly at least 30 years old, and rely heavily on empiricism and contrived conditions for obtaining heat and mass transfer correlations. Development of a general film cooling models that can be used to optimize thermal management and performance are needed, especially models that include effects of entrainment and reacting films. A literature review was performed and mass and heat transfer correlations are summarized, along with the assumptions employed in the analyses and conditions used in the experiments. A model experiment is described, and analysis results based on this experiment are compared. An order of magnitude analysis is used to speculate on the important processes in film cooling, and on the potential benefits of swirling the liquid film to reduce entrainment and provide manageable wall thermal environments at a lower performance penalty.