Investigation of distributor vane jets to decrease the unsteady load on hydro turbine runner blades

• Published in: IOP conference series. Earth and environmental science 2012-11, Vol.15 (2), p.22006
• Main Authors: Lewis, B J, Cimbala, J M, Wouden, A M
• Format: Article
• Language: English
• Subjects: Blades; Computer applications; Distributors; Dynamic loads; Gates; Hydraulic turbines; Jets; Torque; Trailing edges; Turbines; Variation; Velocity
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/15/2/022006

As the runner blades of a Francis hydroturbine pass though the wakes created from the wicket gates, they experience a significant change in absolute velocity, flow angle, and pressure. The concept of adding jets to the trailing edge of the wicket gates is proposed as a method for reducing the dynamic load on the hydroturbine runner blades. Computational experiments show a decrease in velocity variation experienced by the runner blade with the addition of the jets. The decrease in velocity variation resulted in a 43% decrease in global torque variation at the runner passing frequency. However, an increased variation was observed at the wicket gate passing frequency. Also, a 5.7% increase in average global torque was observed with the addition of blowing from the trailing-edge of the wicket gates.