Modeling of Film Cooling—Part I: Experimental Study of Flow Structure

This paper, which is Part I of a two part paper, reports on experimental data taken in a steady flow, flat plate wind tunnel at ETH Zürich, while Part II utilizes this data for calibration and validation purpose of a film cooling model embedded in a 3D CFD code. The facility simulates the film cooling row flow field on the pressure side of a turbine blade. Engine representative nondimensionals are achieved, providing a faithful model at larger scale. Heating the freestream air and strongly cooling the coolant gives the required density ratio between coolant and freestream. The three dimensional velocities are recorded using nonintrusive PIV; seeding is provided for both air streams. Two different cylindrical hole geometries are studied, with different angles. Blowing ratio is varied over a range to simulate pressure side film cooling. The three dimensional flow structures are revealed.