Tandem-blade centrifugal compressor design and optimization by means of 3D inverse design.

Authors

Ricardo João Silva de Oliveira  - Advanced Design Technology, United Kingdom
Luying Zhang - Advanced Design Technology, United Kingdom
Mehrdad Zangeneh - Advanced Design Technology, United Kingdom

Abstract

In centrifugal compressor design, previous studies have shown the potential of achieving enhanced performance through the inclusion of tandem blades. The conventional design method for this type of machines is based in splitting a baseline impeller into main and tandem blade, and applying appropriate pitchwise and streamwise displacements. This simple design method has been proven insufficient in achieving better performance than the baseline design, without extra design modifications. In this paper, a design workflow based in a 3D inverse design method is specifically assembled and applied to the tandem-blade design of centrifugal compressors. The blade geometry is controlled by imposing specified distributions of blade loading in tandem and main blades. Starting from an initial full blade design, different tandem-blade designs are generated using the inverse design methodology. Performance of the initial and optimized designs are then assessed by 3D CFD analysis at design and off-design conditions. The mechanism of performance improvement is investigated in detail. In addition, the structural performance of the generated designs is also assessed by means of FEA.