Full-Coverage Film-Cooling: A One-Equation Model of Turbulence for the Calculation of the Full-Coverage and the Recovery-Region Hydrodynamics

A one-equation model (mixing-length and turbulent kinetic energy) of turbulence is used for the calculation of the full-coverage and recovery region hydrodynamics over a full-coverage film-cooled surface. The model requires a detailed description of the form and dynamics of the complex mixing-length profile encountered in this type of flow structure. This is achieved through extensive use of experimental input and physical interpretation of the data by combining equations for simple flow structures such as two-dimensional turbulent flat plate boundary layers and jets-in-cross flow. The one-equation model is used in a two-dimensional finite difference boundary layer code giving successful predictions of the spanwise averaged mean velocity and turbulent kinetic energy profiles between injection rows in the full coverage region and also in the recovery region for two blowing ratios (Ujet/U∞= 0.4, 0.9).