Optimum Design of Rotational Wheel and Casing Structures Under Transient Thermal and Centrifugal Loads

Abstract

Abstract Transient thermal and centrifugal loads on turbomachinery rotors have increased with recent increases in gas temperatures and tip speeds. Rotor weights must be decreased to improve rotor dynamics and to reduce bearing loads. Moreover, blade tip clearance must be decreased to improve aerodynamic efficiency. An optimum design technique offering the lightest possible wheel shape under specified stress and clearance limits is therefore required. This paper introduces an optimum design system developed for turbo-machinery rotors. Sequential linear programming is used in the optimizing process, and non-steady-state thermal analyses of wheels and casings are performed by numerically analyzing multi-ring models. Stress and deformation analyses of these wheels and casings are performed by using Donath’s method with the same multi-ring model. This optimum design program is applied to the design of multistage axial flow compressor wheels.