A CRITICAL COMPARISON OF NUMERICAL AND EXPERIMENTAL RESULTS FOR THE EXAMINATION OF A CASCADE CONSISTING OF NACA 65-010 1 PROFILES

摘要

Numerical and experimental investigations through different spans of the rotor are a common approach in turbo machinery design. As the aerodynamic quality of rotor blades is crucial for turbo machinery's efficiency, mass-averaged loss coefficients ζ and turning angles ∆β are of particular interest. Using the example of commonly used NACA-65 profiles, a comparison between the results obtained by those methods should investigate whether Computational Fluid Dynamics (CFD) applying the Transition SST turbulence model delivers sufficiently accurate results regarding both 2D and 3D modeling approaches. The comparison is supplemented by the singularity method based on the potential theory as well as historical data provided by NACA. While CFD produced a noticeable offset for some angle configurations, the 2D results of ∆β were in good agreement for singularity method, historical data and experimental investigations on the center line of the cascade supporting the validity of the measurement. Although significant deviations were also found for ζ, it can be stated that CFD reproduced the qualitative course sufficiently for both variables considered. A similar picture emerges from the 3D comparison: Despite noticeable deviations in quantitative terms, a good correspondence was found for both variables regarding local and mass-averaged values.