Roberto Renato Stopar attended the conference ‘Kuhljevi dnevi 2017′ in Terme Dobrna, Slovenia, on 28th of Sept.
Every year, the Slovene association for Mechanics (Slovensko društvo za mehaniko) organizes conference Kuhljevi dnevi on memory of Slovene scientist Anton Kuhelj. This year the conference was in Terme Dobrna from 28th to 29th of September.
Roberto presented the paper:
Multiobjective optimization of a hydraulic shape of runner cone extension in Francis turbine
Authors: R. R. Stopar, A Škerlavaj and E Nobile
A multi-objective optimization with a genetic algorithm MOGA-II was used to optimize the shape of a simplified runner-cone extension (RCE) for a Francis turbine of higher specific speed nq. The objective of the optimization was the minimization of the draft tube pressure losses for two operating regimes. To evaluate the progress, a baseline case without the extension was calculated first. Six geometric design variables, defining the shape of RCE, were being modified during the optimization. Finite-volume based commercial software ANSYS CFX was employed to calculate the flow field on a structured mesh. Shapes of RCE on Pareto front were long and thin. At the best-efficiency point (BEP) the draft tube pressure losses were larger than without the RCE. At the maximal discharge point (MAX) the draft tube pressure losses were smaller than without the RCE, turbine efficiency increases for 0,15% at full size computation grid.
The full-text (in Slovenian) can be found in the Proceedings of the conference.