TY - JOUR

T1 - An Overview of Active Control Techniques for Vortex Rope Mitigation in Hydraulic Turbines

AU - Shtork, Sergey

AU - Suslov, Daniil

AU - Skripkin, Sergey

AU - Litvinov, Ivan

AU - Gorelikov, Evgeny

N1 - The study described in Section 3 was supported by the Russian Science Foundation (Project No. 21-19-00769). Part of review presented in Section 2 was carried out under state contract with Institute of Thermophysics Siberian Branch of the Russian Academy of Sciences (Project No. 121031800229-1).

PY - 2023/7

Y1 - 2023/7

N2 - This review addresses the current state of research into active control and suppression of vortex rope in hydroturbines under off-design operating conditions. Only active control methods that can be “switched on” when required under off-design operating conditions are considered in this work. The review focuses on air addition into the flow, as well as various auxiliary fluid jets. It includes all the best practices for vortex rope suppression in numerical and experimental studies. It can be inferred from the review that a modern flow control system should be comprehensive, designed for a specific hydroturbine geometry, and obtain feedback from the flow. Injecting ~2% of air from the impeller fairing cone appears optimal for suppressing pressure pulsations without significant efficiency loss. The cost of air injection is rarely estimated, but the use of an automatic venting system can minimize overheads and potentially improve efficiencies at low gas contents. Fluid jets ranging from 3% to 12% of the main flow rate can efficiently suppress pressure pulsations, but their high energy requirements limit their use. Azimuthal perturbation of the flow appears promising as it does not require significant energy loss, but practical implementation remains challenging as one needs to accurately know the system dynamics and be capable of real-time manipulation of the flow.

AB - This review addresses the current state of research into active control and suppression of vortex rope in hydroturbines under off-design operating conditions. Only active control methods that can be “switched on” when required under off-design operating conditions are considered in this work. The review focuses on air addition into the flow, as well as various auxiliary fluid jets. It includes all the best practices for vortex rope suppression in numerical and experimental studies. It can be inferred from the review that a modern flow control system should be comprehensive, designed for a specific hydroturbine geometry, and obtain feedback from the flow. Injecting ~2% of air from the impeller fairing cone appears optimal for suppressing pressure pulsations without significant efficiency loss. The cost of air injection is rarely estimated, but the use of an automatic venting system can minimize overheads and potentially improve efficiencies at low gas contents. Fluid jets ranging from 3% to 12% of the main flow rate can efficiently suppress pressure pulsations, but their high energy requirements limit their use. Azimuthal perturbation of the flow appears promising as it does not require significant energy loss, but practical implementation remains challenging as one needs to accurately know the system dynamics and be capable of real-time manipulation of the flow.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85164972996&origin=inward&txGid=dddb4026b686fd742a1f6203a395c0dd

U2 - 10.3390/en16135131

DO - 10.3390/en16135131

M3 - Article

VL - 16

JO - Energies

JF - Energies

SN - 1996-1073

IS - 13

M1 - 5131

ER -