The Optimisation of Stator Vane Settings in Multi-stage Axial Compressors Using A Particle Swarm Optimization Method

Axial flow compressors are required to operate over a wide range of mass flow rate and rotational speeds at high efficiency in industrial gas turbines. However, the useful range of operation of the axial compressor is limited by the onset of two instabilities known as surge and rotating stall. To resolve these problems, variable stator blades or VGVs are considered by optimising the blade setting in order to avoid the stall and subsequent surge. To investigate performance, particularly obtaining acceptable convergence time for practical purposes, a steady state model of a 15 stage multi-axial compressor is utilised. For the effective search for an optimum setting, the variation in VGVs with respect to a different combination of objective functions is considered. In this paper, a particle swarm optimisation method with time-varying inertia weight factor was proposed and utilised to obtain the best value for a normalised objective function. The results of PSO demonstrate the effectiveness and the suitability of its use in this proposed application.