This paper was exhibited at the Turbomachinery Society of Japan in 2017 and it explores a complete multipoint optimisation methodology about the meridional geometry and the blade loading (blade shapes) of the impeller, the vaned diffuser, crossover bend and the vaned return channel using 3D inverse design method, DOE (Design of Experiments), Kriging RSM (Response Surface Model) and MOGA (Multi-Objective Genetic Algorithm).
In this method, the flow field is divided into a mean flow part and a periodic flow part. The mean flow equation is solved by using Stokes stream function for axial-symmetric flow. The periodic flow equation is solved by using discrete Fourier transformation.
The final optimal design shows improved flow field in all components and around 1% efficiency
improvement in a wide operating range based on CFD.