Rotating vortex rope formation and mitigation in draft tube of hydro turbines–A review from experimental perspective

S Kumar, MJ Cervantes, BK Gandhi - Renewable and Sustainable Energy …, 2021 - Elsevier
Hydropower is a clean and renewable source of energy which is widely used to generate
electric power and stabilize the power grid. It can respond quickly to any change in demand …

A review on remedial attempts to counteract the power generation compromise from draft tubes of hydropower plants

A Muhirwa, WH Cai, WT Su, Q Liu, M Binama, B Li… - Renewable Energy, 2020 - Elsevier
Hydropower plants provide an asset over other renewables of production flexibility. Away
from the turbine design point; detrimental off-load instabilities may compromise the power …

Investigation of cavitating vortex rope instabilities and its suppression inside a Francis turbine model with Thoma number variation

MA Shahzer, Y Cho, MM Shamsuddeen, JH Kim - Physics of Fluids, 2023 - pubs.aip.org
Cavitating vortex rope at part load (PL) condition at lower values of the Thoma number (r)
induces severe pressure fluctuation and efficiency reduction in a Francis turbine, which …

Optimization of axial water injection to mitigate the Rotating Vortex Rope in a Francis turbine

HJ Juposhti, R Maddahian, MJ Cervantes - Renewable Energy, 2021 - Elsevier
Abstract Rotating Vortex Rope (RVR) resulting from flow instabilities inside draft tube affects
the hydraulic turbine's efficiency and wear. Among the passive and active RVR mitigation …

Suppression of vortex rope formation and pressure fluctuation using anti-swirl fins in a Francis turbine model at part load condition with cavitation inception point

MA Shahzer, SJ Kim, Y Cho, JH Kim - Physics of Fluids, 2022 - pubs.aip.org
Vortex rope formation at part load (PL) with cavitation inception causes pressure fluctuations
inside the draft tube (DT) of a Francis turbine which may fail the turbine due to resonance …

Investigation on combined air and water injection in Francis turbine draft tube to reduce vortex rope effects

M Mohammadi, E Hajidavalloo… - Journal of Fluids …, 2019 - asmedigitalcollection.asme.org
In this paper, the effect of water, air, and their combined injection from two different injection
points is studied in order to reduce vorticity effects in a draft tube of prototype turbine working …

Experimental study of mitigation of a spiral vortex breakdown at high Reynolds number under an adverse pressure gradient

R Goyal, BK Gandhi, MJ Cervantes - Physics of fluids, 2017 - pubs.aip.org
The flow in the off-design operation of a Francis turbine may lead to the formation of spiral
vortex breakdowns in the draft tube, a diffuser installed after the runner. The spiral vortex …

Aspects of vortex breakdown phenomenon in hydraulic turbines

FA Masoodi, R Goyal - Experimental Thermal and Fluid Science, 2024 - Elsevier
Operational flexibility of hydraulic turbines is impeded by the vortex breakdown
phenomenon. The phenomenon, a consequence of instability in vortical flows in general …

Linear global stability analysis of a transient swirling flow leading to the formation of a helical precessing vortex breakdown in a straight diffuser

Z Seifi, M Raisee, MJ Cervantes - European Journal of Mechanics-B/Fluids, 2024 - Elsevier
Vortex breakdown occurs in highly swirling flows in various engineering applications, such
as hydraulic turbines working in either high-load or part-load conditions, leading to pressure …

Francis turbine draft tube troubleshooting during operational conditions using CFD analysis

M Mohammadi, E Hajidavalloo, M Behbahani-Nejad… - Water, 2023 - mdpi.com
Hydropower plant vibrations due to pressure fluctuations and their troubleshooting methods
are some of the most challenging issues in power plant operation and maintenance. This …