Study of Flow Characteristics inside Francis Turbine Draft Tube with Adjustable Guide Vanes

Numerical investigation was performed on a semi-model (one stay vane, two guide vanes, one runner passage inclusive of main and splitter blade, the draft tube) high-head Francis turbine model with adjustable vanes in tube. The motive present study is to investigate possibility mitigate rotating vortex rope (RVR) formed at part load operating condition. Each vane tube consists hydrofoils. upper hydrofoil according flow angles leaving runner. lower stationary corresponds angle best efficiency point (BEP).The factors considered while designing these were a) number b) chord length, c) span d) position preliminary results indicate that RVR pressure amplitude suppressed by 97% compared reference no (PL) An 8.7% increment recovery obtained which indicates implementation could positively impact beside mitigation pulsations PL operation.