Vpliv lokalne spremembe geometrije lopatic radialne črpalke na pojav kavitacije

Cizl, Primož (author), Hočevar, Marko (mentor), Novak, Lovrenc (comentor)

Pojav kavitacije zmanjšuje življenjsko dobo rotorja in kvari karakteristike, za katere je bila črpalka projektirana. S pomočjo računalniške dinamike tekočin smo analizirali vpliv lokalne spremembe izhodiščne geometrije rotorja na pojav kavitacije. Med spremembami geometrije rotorja smo obravnavali premik in nagib vodilnega roba lopatic in ocenili njune posledice na karakteristiko črpalke. Uspešnost posamezne spremembe smo ovrednotili z lokalnimi spremenljivkami, kot so diskretne vrednosti skupne prostornine kavitacijskih mehurčkov in porazdelitve tlakov. Tokovne razmere smo predstavili tudi vizualno. Ugotovili smo, da spremembe, ki zmanjšajo verjetnost za pojavljanje kavitacije, poslabšajo delovne karakteristike črpalke. To hkrati tudi pomeni, da lahko za vsako črpalko s spremembami geometrije vodilnega roba lopatice in glede na značilnosti obratovanja izberemo, za katero spremenljivko želimo, da ima optimalne vrednosti.

• Language: Slovenian
• Keywords: radialne črpalke, kavitacija, primerjava rotorjev, sprememba geometrije, računalniška dinamika tekočin, parametri obratovanja, rotorji, lopatice
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Year: 2025
• Number of pages: XX, 73 str.
• PID: 20.500.12556/RUL-169409
• UDC: 621.671:532.528:004(043.2)
• COBISS.SI-ID: 240821507
• Publication date in RUL: 28.05.2025

Secondary language

• Language: English
• Title: The impact of local blade geometry changes in a radial pump on cavitation occurrence

Abstract

The occurrence of cavitation reduces the lifespan of the rotor and deteriorates the characteristics for which the pump was designed. Using computational fluid dynamics, we analyzed the impact of local changes in the initial rotor geometry on the occurrence of cavitation. Among the changes in rotor geometry, we addressed the sweep and lean of the leading edge of the blades and evaluated their consequences on the pump's characteristics. The effectiveness of each change was assessed using local variables, namely the discrete values of the total volume of cavitation bubbles and the pressure distributions. Flow conditions were visually presented. We found that the changes that reduce the likelihood of cavitation occurrence worsen the pump's operating characteristics. This also means that, for each pump, we can choose, based on the changes in the geometry of the leading edge of the blade and the operating characteristics, which variable we want to have optimal values for.

• Keywords: radial pumps, cavitation, comparison of rotors, geometry modifications, computational fluid dynamics, operating parameters, rotors, blades