o:2117 Numeričko eksperimentalna istraživanja nestacionarnih strujanja u postrojenjima sa cross-flow turbinama Numerical and experimental research of unsteady flow in hydropower plants with cross-flow turbines : doctoral dissertation sr Transients in hydropower plants can result in serious disturbances in aplant operation and damage of equipment. The best way to prevent suchadverse outcomes is to conduct a transient-state analysis using amathematical model of the hydropower plant system.Based on the collected data on 270 hydropower plants with cross-flowturbines, regression analyses were done and regression equations werederived that relate a cross-flow turbine specific speed (ns), turbine ratedspeed (nt), turbine runner diameter (D1) and turbine runner width (B1)and jet (B) as a function of turbine head and discharge.The obtained equations were used to estimate the turbine performancecharacteristics using available unit hill charts of three different cross-flowturbines (ns=45.7, 68.8 i 93.4). Finally, the estimated performancecharacteristics were used to form the boundary condition “CROSSFLOWTURBINE” within the unsteady 1D mathematical model.The model was validated through case studies by comparing calculatedand measured changes in the turbine speed and turbine inlet pressure,induced by sudden load rejection. The difference between the calculatedand measured peak pressures was up to 10% during the critical period,(from the moment of load rejection up to the guide vanes closure). In thecase of turbine speed, the difference between the peak values was lessthan 10% in the same period. Bibliografija: str. 146-149 Datum odbrane: 13.10.2023. Energy and process technology 91552100 131715593 91552101 8644 2023-12-15T16:06:54.053Z 45 no 46 Dragan M., 1962- Svrkota 107704841 2023 63 mentor Živojin, 1972- Stamenković 14288999 2023 63 član komisije Slobodan Tašin 2023 63 član komisije Jasmina Bogdanović Jovanović 2023 63 član komisije Živan Spasić 2023 63 član komisije Miloš Kocić 2023 [8], 161 str. 13590772 http://phaidrani.ni.ac.rs/o:2117 no yes 12 2023-12-15T16:06:54.320Z 70 Cross-flow turbina, jedinične karakteristike, školjkasti dijagram,hidroelektrana, ispad, nestacionarni režimi, hidraulički udar Cross-flow turbine, unit characteristics, hill chart, hydropower plant, loadrejection, transients, water hammer 621.224(043.3) T 210 1738 18A04 18A0404 2023