Numerical Investigation of the Influence of Real World Blade Profile Variations on the Aerodynamic Performance of Transonic Nozzle Guide Vanes

This paper addresses the issue of aerodynamic consequences of variations in airfoil profile. An analysis of new and repaired airfoils was used to synthesize profiles representative of specific repair types. Five variations of a reference new low pressure turbine vane were obtained by changing the characteristic parameters of trailing-edge tweaking and laminate-repair methods used to refurbish turbine vanes. Flow visualization of shock structure and total pressure measurements were made by experimentation in a cascade rig and by calculations through Computational Fluid Dynamics (CFD). The performance of the modified profiles was compared with that of the reference new vane. The total pressure losses increased when the profile was bent at the trailing edge towards the pressure side. The losses for synthesized laminate repair profiles increased with an increase in the thickness of laminate repair. The numerical results were used to supplement experimental results in cases where the experimental conditions were not representative of typical design operating conditions.Copyright © 2011 by ASME