Numerical and Experimental Study of Trenched Film Hole Cooling for a Realistic Cascade in an Annular Endwall, Phase 1: Test Rig Construction and Preliminary Data

摘要

This is a preliminary numerical and experimental study on the film cooling effectiveness. Film cooling holes will be employed in the stagnation region (inner-diameter endwall or hub endwall) of GE-E3 first stage rotor blades of a high pressure turbine in a subsonic commercial aircraft. For deeper understanding of interaction behavior between film cooling jets and secondary flows inside the cascade passage, a realistic (0.8 Mach number) annular test rig has been built and completed in the CATER laboratory. Five (four and two halves) 3D profile airfoils are used to gain a periodic flow for the middle passage. The experimental test rig is a 3X scaled of the real engine geometry. It has an inner diameter surface of 970 mm and outer diameter surface of 1098 mm. It is the middle passage where all the measurement has been measured. A RANS numerical model has been simulated and is used to validate the experimental data and the existing open literature. The computational fluid dynamic simulation models a steady annular cascade with five realistic airfoils (4 and 2 halves). The computational fluid dynamic model is simulated using a commercial package. It is the computational fluid dynamic model will also be used to extract all the necessary data for the sensitivity analysis while certain cases will be parallel validated against with experimental data. Preliminary pressure and velocity data have been mapped and will be presented at this phase. The obtained data are useful and help the current investigation move forward. Detail study of interaction characteristic between trenched film cooling jets and the main stream will be reported in the next phase and parameter sensitivities analysis on the film cooling effectiveness and cooling uniformity coefficient using response surface methodology will also explicitly introduced.