Measurements of cavitation vortex rope pressure pulsations in a radial water pump

V diplomski nalogi se obravnava področje tlačnih nihanj v centrifugalni črpalki. Opisani in predstavljeni so osnovni sklopi hidravličnih turbinskih strojev, osnove in teoretično ozadje centrifugalnih črpalk ter kavitacije. Prikazan in opisan je postopek postavitve merilnega postrojenja, izvedba meritev, opisana uporaba merilnih komponent in uporabljenih programov. Poleg tega so analizirani dobljeni rezultati, ki so predstavljeni v obliki grafov in komentarjev. Analiza ponovljivosti meritev je prikazala dobro ponovljivost rezultatov pri podobnih obratovalnih režimih. Primerjali smo tudi meritve z vakuumom in brez vakuuma v merilnem sistemu ter prišli do ugotovitve, da so amplitude frekvenc višje pri meritvah, ko je v merilnem sistemu za analizo kavitacijskih karakteristik radialne črpalke prisoten vakuum. V primeru uporabe čepa v sesalni cevi črpalke smo prišli do sklepa, da velikost čepa vpliva na dušenje tlačnih nihanj, ki jih merimo s hidrofonom.The diploma thesis deals with the field of pressure oscillations in a centrifugal pump. The sets of bases of hydraulic turbomachinery, bases and theoretical background of a centrifugal pump and cavitation are described and presented. The process of setting up a measuring system, performing measurements, describing the use of measuring components and the programs used are also described. In addition, the obtained results are analysed and presented in the form of graphs and comments. Measurement repeatability analysis showed good repeatability of results under similar operating regimes. We also compared measurements with vacuum and without vacuum in the measuring system and came to the conclusion that the frequency amplitudes are higher in the measurements when vacuum is present in the measuring system for the analysis of cavitation characteristics of the radial pump. In the case of using a plug in the suction pipe of the pump, we concluded the size of the plug affects the damping of pressure fluctuations, which measured with a hydrophone