Aerodynamic design of a fan for high speed propulsion

Abstract

Consulta en la Biblioteca ETSI Industriales (8410)

[EN] Air turbo rocket engines are used to accelerate vehicles to hypersonic speeds. In the frame of the European project LAPCAT II, the design methodology for a transonic-supersonic fan was propposed and applied to a single-stage fan. The purpose of the present project is to confirm the consistency of the established methodology. Investigation on a two contra-rotating stages configuration was as well performed. The meridional plane design was addressed with the VKI Axial Compressor Design algorithm. Both, parametric analysis and Design Optimization techniques, were carried out for the single-stage and two contra-rotating stages cases respectively. Design-Optimization strategy with Evolutionary Algorithm was then applied for the 2D blade-to-blade design. Two different parametrizations of the 2D section were developed. An automatic mesh generation procedure, combined with the Navier-Stokes solver TRAF, enabled a robust assessment of aerodynamic performances for several geometries within a wide design space. Two-dimensional sections were designed for minimum losses and a limited outlet angle offset from the desired value (+/- 0,1 degree). Optimal subsonic profiles presented controlled diffusion on the suction side with attached flow until the trailing edge. Transonic and supersonic profiles were optimized to reduce the shocks losses. The complete performance map was computed with the 3D blade built by stacking the 2D optimized sections at different blade heights. The design methodology was validated at this point of the project, since the 3D results obtained matched the design point conditions predicted by the meridional plane design.