Particle Deposition in Internal Cooling Cavities of a Nozzle Guide Vane: Part I — Experimental Investigation

Abstract

An experimental facility was fabricated to simulate particle deposition on the internal wall of a nozzle guide vane cooling cavity. The facility supplied particle-laden flow at temperatures up to 540°C to a simplified impingement cooling test section. The heated flow passed through a perforated film hole plate and impacted on the internal surface of a vane wall. The particle-laden impingement jets resulted in the buildup of deposit cones associated with individual impingement jets. The deposit growth rate increased with flow temperature and when the film hole plate temperature was elevated with backside heating. At low temperatures, deposit formed not only as individual cones, but as ridges located at the mid-planes between impinging jets. The base diameter of the deposit structures were found to be larger than the impingement hole diameter due in part to an aerodynamic lensing effect. Further studies using a test piece with optical access were used to document the evolution of deposit cones during continuous deposition.