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

Abstract

This paper, which is Part I of a two part paper, reports on new experimental data taken in a steady flow, flat plate wind tunnel at ETH Zu¨rich, while Part II utilizes this data for calibration and validation purpose of a new 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 non-dimensionals are achieved, providing a faithful model at larger scale. Heating the free stream air and strongly cooling the coolant gives the required density ratio between coolant and free-stream. The three dimensional velocities are recorded using non-intrusive 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.