Development of high specific speed Francis turbine for low head HPP

Development of high specific speed Francis turbine for low head HPP

Článek recenzovaný mimo WoS a Scopus

Nowadays we can commonly encounter with revitalizations of an original HPPs which were earlier fitted with Francis turbines. They were often placed to the locations with low head and higher discharge which means high specific speed (ns > 400). Generally it is quite complex to design Francis turbines for such high specific speed. These very old turbines usually have lower efficiency due to the earlier limited possibilities of hydraulic design. An exchange of a water turbine with another type can be quite expensive and therefore it can be more suitable to change only an old runner for a new one. In this article the design process of high specific speed turbine ns = 430 is described. Optimization was done as the full-automatic cycle and was based on a simplex optimization method as well as on a genetic algorithm. For the parameterization of the runner blade, the BladeGen software was used and CFD (Computational Fluid Dynamics) analysis was run in Ansys CFX v.14 software. The final shape of the runner blade was reached after computing about 1000 variants which lasted about 250 computational hours.

Nowadays we can commonly encounter with revitalizations of an original HPPs which were earlier fitted with Francis turbines. They were often placed to the locations with low head and higher discharge which means high specific speed (ns > 400). Generally it is quite complex to design Francis turbines for such high specific speed. These very old turbines usually have lower efficiency due to the earlier limited possibilities of hydraulic design. An exchange of a water turbine with another type can be quite expensive and therefore it can be more suitable to change only an old runner for a new one. In this article the design process of high specific speed turbine ns = 430 is described. Optimization was done as the full-automatic cycle and was based on a simplex optimization method as well as on a genetic algorithm. For the parameterization of the runner blade, the BladeGen software was used and CFD (Computational Fluid Dynamics) analysis was run in Ansys CFX v.14 software. The final shape of the runner blade was reached after computing about 1000 variants which lasted about 250 computational hours.

Francis turbine, high specific speed, CFD, optimization method, objective function

Francis turbine, high specific speed, CFD, optimization method, objective function

KRAUSOVÁ, H.; OBROVSKÝ, J.; ŠPIDLA, J.; ZOUHAR, J.

06.12.2013

Association for Engineering Mechanics

Praha

1802-1484

Engineering Mechanics

20

2

Česká republika

139

148

10