Multi-fidelity design optimization of Francis turbine runner blades

27th IAHR Symposium on Hydraulic Machinery and Systems

Bahrami, S.^1 ; Tribes, C.^1 ; Von Fellenberg, S.^2 ; Vu, T.C.^2 ; Guibault, F.^1

École Polytechnique de Montréal, Montreal

QC, Canada^1

Andritz Hydro Ltd, Pointe-Claire

QC, Canada^2

关键词: Computational effort;    Computational task;    Derivative-free optimization;    Design optimization;    Different geometry;    Francis turbine runner;    Industrial hydraulics;    Optimization solution;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/22/1/012029/pdf
DOI  :  10.1088/1755-1315/22/1/012029

来源: IOP

【 摘 要 】

A robust multi-fidelity design algorithm has been developed, focusing to efficiently handle industrial hydraulic runner design considerations. The computational task is split between low- and high-fidelity phases in order to properly balance the CFD cost and required accuracy in different design stages. In the low-fidelity phase, a derivative-free optimization method employs an inviscid flow solver to obtain the major desired characteristics of a good design in a relatively fast iterative process. A limited number of candidates are selected among feasible optimization solutions by a newly developed filtering process. The main function of the filtering process is to select some promising candidates to be sent into the high-fidelity phase, which have significantly different geometries, and also are dominant in their own territories. The high-fidelity phase aims to accurately evaluate those promising candidates in order to select the one which is closest to design targets. A low-head runner case study has shown the ability of this methodology to identify an optimized blade through a relatively low computational effort, which is significantly different from the base geometry.