A Correlation-Based Methodology to Predict the Flow Structure of Flows Emanating from Cylindrical Holes with Application to Film Cooling

摘要

This paper presents a methodology to predict the flow structure of cooling flows emanating from cylindrical film-cooling holes based on characteristic flow parameters. The dependence of the film-jet flow field on characteristic flow parameters, such as blowing ratio and density ratio, has been studied using a validated high-resolution computational fluid dynamics model of a film-cooled flat plate. For the film-jet flow structure, mathematical formulations have been developed based on physical and empirical considerations. Free coefficients in the proposed formulations have been adjusted using a least-square-fit method to match the results from the detailed flow simulations qualitatively and quantitatively. To establish a functional relationship between the least-square-fit coefficients and the film cooling parameters, models have been developed and optimized using analysis of variance. These models provide the capability to predict the proper choice of coefficients based on the film cooling parameters. The combination of coefficient models and mathematical formulations allows the prediction of the complete three-dimensional flow field of the film-jet-body in the vicinity of a film cooling ejection site.