Systematic Investigation on Swept and Leaned Transonic Compressor Rotor Blades

A systematic investigation to understand the impact of axial sweep and tangential lean on the aerodynamic behavior of transonic axial-flow compressor rotors was undertaken. A commercial CFD package which solves the Reynolds-averaged Navier-Stokes equations was used to compute the complex flow field of these machines. The code was validated against NASA Rotor 37 existing experimental data. Computed performance maps and downstream profiles showed a good agreement with measured ones. Furthermore, comparisons with experimental data indicated that the overall features of three-dimensional shock structure, shock-boundary layer interaction, and tip clearance flows can be calculated well using the code. Quite a large number of new transonic swept rotors (26) were modeled starting from the Rotor 37, by changing systematically the meridional curvature of the original stacking line using three previously defined control points. Similarly, 26 new transonic leaned rotors were modeled. All the new transonic rotors were simulated and numerical results revealed many interesting aspects which are believed to be very helpful to better understand the blade curvature effects on shock and secondary losses, giving insights on possible optimization techniques.