On the Aerodynamics of Swept and Leaned Transonic Compressor Rotors

Abstract

A systematic investigation to understand the impact of axially swept and tangentially leaned blades on the aerodynamic behaviour of transonic axial flow compressor rotors was undertaken. Effects of axial and tangential blade curvature were separately analyzed. A commercial CFD package which solves the Reynolds-average Navier-Stokes equations was used to compute the complex flow field of transonic compressor rotors. The code was validated against NASA Rotor 37 existing experimental data. Computed performance maps and downstream profiles showed a very good agreement with measured ones. Furthermore, comparisons with experimental data indicated that the overall features of the three-dimensional shock structure, the shock-boundary layer interaction, and the wake development are calculated very well in the numerical solution. Next, a quite large number of new transonic swept rotors (26) were modeled from the original Rotor 37, by changing the meridional curvature of the original stacking line through three previously defined control points (located at 33%, 67% and 100% of the span). An attempt was made to not modify any other design parameter. In particular, in order to isolate the influence of sweep on the aerodynamic behaviour of the new rotors, the meridional position of the tip blade profiles was not changed. Similarly, 26 new transonic leaned rotors were modeled from the same Rotor 37 by changing the circumferential position of the same control points. All the new transonic rotors were simulated and the results revealed many interesting aspects which are believed to be very helpful to better understand the blade curvature effects on the shock and secondary losses within a transonic rotor.