Large Scale Optimization of Transonic Axial Compressor Rotor Blades

Abstract

[First Paragraphs]
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\nIn the present work the Multipoint Approximation Method (MAM) by Toropov et al. (1993) has been applied to
\nthe shape optimization of an existing transonic compressor rotor (NASA rotor 37) as a benchmark case.
\nSimulations were performed using the Rolls-Royce plc. PADRAM-HYDRA system (Shahpar and Lapworth 2003,
\nLapworth and Shahpar 2004) that includes the parameterization of the blade shape, meshing, CFD analysis, postprocessing,
\nand objective/constraints evaluation. The parameterization approach adopted in this system is very
\nflexible but can result in a large scale optimization problem.
\n
\nFor this pilot study, a relatively coarse mesh has been used including around 470,000 nodes. The
\nparameterization was done using 5 engineering blade parameters like axial movement of sections along the engine
\naxis in mm (XCEN), circumferential movements of sections in degrees (DELT), solid body rotation of sections in
\ndegrees (SKEW), and leading/trailing edge recambering (LEM0/TEMO) in degrees. The design variables were
\nspecified using 6 control points at 0 % (hub), 20%, 40%, 60%, 80%, and 100% (tip) along the span. Thus the total
\nnumber of independent design variables N was 30. B-spline interpolation was used through the control points to
\ngenerate smooth design perturbations in the radial direction.