Impact of Non-Uniform Leading Edge Coatings on the Aerodynamic Performance of Compressor Airfoils

A computational fluid dynamic (CFD) investigation is presented that provides predictions of the aerodynamic impact of uniform and non-uniform coatings applied to the leading edge of a compressor airfoil in a cascade. Using a NACA 65(12)10 airfoil, coating profiles of varying leading edge non-uniformity were added. A non-uniform coating is obtained when a liquid coating is applied to a surface with high curvature, such as an airfoil leading edge. The CFD code used, RVCQ3D, is a Reynolds Averaged, Navier-Stokes (RANS) solver, with a k-omega turbulence model. The code predicted that these changes in leading edge shape can lead to alternating pressure gradients in the first few percent of chord that create small separation bubbles and possibly early transition to turbulence. The change in total pressure loss and trailing edge deviation are presented as a function of a coating non-uniformity parameter. Results are presented over a range of negative and positive incidences and inlet Mach numbers from 0.6 to 0.8. A map is provided that shows the allowable degree of coating non-uniformity as a function of incidence and inlet Mach number.Copyright © 2005 by ASME