Postopek oblikovanja profila lopatice Kaplanove turbine za ublažitev pojava kavitacije pri velikih pretokih

Podnar, Andrej (author), Hočevar, Marko (mentor)

Raziskan je bil vpliv spremembe oblike dveh profilov kot sestavnih gradnikov lopatic gonilnikov Kaplanove turbine na pojav kavitacije. Cilj je izboljšati kinematiko vodnega toka okoli lopatic Kaplanovega gonilnika in s tem zmanjšanje pojava kavitacije na gonilnih lopaticah. Pričakovana posledica zmanjšanja kavitacije je poleg daljše življenjske dobe gonilnika tudi povečanje izkoristka turbine. Obsežna analiza kavitacijskih struktur je bila izvedena na dveh profilih in dveh gonilnikih. Obsegala je meritve integralnih veličin, vizualizacijo topoloških struktur, časovnih vrst in dinamiko obtekajočih tokov. Na podlagi teh analiz pa je bil razvit tudi kavitacijski model za napoved nastanka kavitacije glede na glavne vhodne parametre toka. Rezultati potrjujejo pravilno spremembo oblike profila in posledično oblike gonilnih lopatic glede na zmanjšanje nastanka kavitacijskih struktur. Potrjeno je bilo zmanjšanje nastanka kavitacijskih struktur in povečanja hidrodinamskega izkoristka modelne turbine.

• Language: Slovenian
• Keywords: Kaplanove gonilne lopatice, kavitacijski model, lopatice Kaplanovih gonilnikov, gradniki lopatic, profili, kinematika in dinamika obtekajočih tokov, pojav kavitacije in kavitacijske strukture, kavitacijski oblaki, profili v kavitacijskem kanalu, tlačne pulzacije v pretočnem traktu modelne turbine, računalniško podprta vizualizacija, modelni preizkus turbin
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [A. Podnar]
• Year: 2024
• Number of pages: XVII, 120 str.
• PID: 20.500.12556/RUL-158743
• UDC: 621.224.35:532.528:531.2(043.3)
• COBISS.SI-ID: 202608899
• Publication date in RUL: 20.06.2024

Secondary language

• Language: English
• Title: Kaplan turbine blades profile design procedure for cavitation mitigation at high flow rates

Abstract

By changing the profile hydrodynamic shape, two different profiles were studied for circumferential fluid kinematics and the occurrence of cavitation in order to reduce cavitation phenomena on Kaplan turbine runner blades and consequently improve energy performance. For the analysis of the results, a large amount of data were obtained by means of measurements of integral quantities and visually with the help of computer-aided visualization on profiles in the cavitation tunnel and Kaplan runner blades on the test rig for model tests. The experiment results indicate a proper in a good correlation between the shape of profile and cavitation phenomena. Confirmation of the correct shape correction on profiles was made by testing two different runner blade shapes.

• Keywords: Kaplan water turbine, cavitation model, Kaplan turbine blades, air foils as turbine blade components, kinematics and dynamics of flowing flows, phenomenon of cavitation and cavitation structure, cavitation clouds, air foils in the cavitation channel, Pressure pulsation in the Hydraulic Passage of the model turbine, computer aided visualization, turbine model tests