Improving Aerodynamic Matching of Axial Compressor Blading Using a Three-Dimensional Multistage Inverse Design Method

Abstract

Current turbomachinery design systems increasingly rely on multistage CFD as a means to diagnose designs and assess performance potential. However, design weaknesses attributed to improper stage matching are addressed using often ineffective strategies involving a costly iterative loop between blading modification, revision of design intent, and further evaluation of aerodynamic performance. A scheme is proposed herein which greatly simplifies the design point blade row matching process. It is based on a three-dimensional viscous inverse method that has been extended to allow blading analysis and design in a multi-blade row environment. For computational expediency, blade row coupling is achieved through an averaging-plane approximation. To limit computational time, the inverse method was parallelized. The proposed method allows improvement of design point blade row matching by direct regulation of the circulation capacity of the blading within a multistage environment. During the design calculation, blade shapes are adjusted to account for inflow and outflow conditions while producing a prescribed pressure loading. Thus, it is computationally ensured that the intended pressure-loading distribution is consistent with the derived blading geometry operating in a multiblade row environment that accounts for certain blade row interactions. The viability of the method is demonstrated in design exercises involving the rotors of a 2.5 stage, highly loaded compressor. Individually redesigned rotors display mismatching when run in the 2.5 stage, evident as a deviation from design intent. However, simultaneous redesign of the rotors in their multistage environment produces the design intent, indicating that aerodynamic matching has been achieved.

Implementation of Three-Dimensional Inverse Design and Its Application to Improve the Compressor Performance

“…A similar principle was also described in the study of Demeulenaere and Van den Braembussche [9]. In terms of the application of inverse design, some achievements have been made in swept blades, the suppression of secondary flow, multipoint design, blade optimization, and multistage matching [10][11][12][13]. However, these inverse design methods have not been widely used.…”

An improved inverse method for multirow blades of turbomachinery

“…In the existing literature, only Van Rooij et al. 17,18 have systematically studied the blade rows matching problem via three-dimensional inverse design method. They developed a pressure loading manager, which can automatically adjust pressure loading distributions to adapt the interaction between the rotor and stator.…”

Automatic Design of Turbomachinery Blading Using GPU Accelerated Adjoint Compressible Flow Analysis

“…Most published works describe just 2D aerodynamic design problems, for example Li et al [112]. Applications to the full three dimensional problem, while more scarce, do exist (see Wang and Li [113] and van Rooij et al [114]).…”