V-Shaped Holes for Full Coverage Film Cooling of a High-Pressure Nozzle Guide Vane

This paper describes an experimental activity carried out to investigate the potential of V-shaped holes for film cooling a high-pressure nozzle guide vane. The newly designed V-shaped scheme was compared with standard laidback fan-shaped holes. The influence of showerhead cooling was also assessed. Different injection conditions were examined under the same cascade operating condition using CO2 as a coolant. The quality of holes geometry and their discharging behavior was first characterized. Then, dual-luminophore pressure-sensitive paint (PSP) was used for measuring the adiabatic film cooling effectiveness all over the vane surface. Results of the current work showed that using a V-shaped hole configuration would give nearly the same surface protection as standard shaped holes with a reduced number of holes and, thus, at lower coolant flow consumption.