1315 KB11 KB201320252017Fike, MatejHribernik, Alešletnik:10številka:iss. 3str. 25-32ISSN:1855-5748COBISSID:21056790URN:URN:NBN:SI:doc-H0BPUAWFenFakulteta za energetikoJET on-lineJournal of energy technologyAnsys CFXceviCFDelbow draft tubenumerical analysisnumerična analizaračunalniška dinamika tekočinturbineInfluence of tail water level on the hydraulic performance of elbow draft tube| Vpliv spodnje vode na hidravlične karakteristike sesalne cevi|Numerical simulations of the flow in the elbow draft tube of a Kaplan turbine were carried out in order to elucidate the effects of tail water level on draft tube performance and flow stability. The influence of the tail water level is explored considering the correct boundary condition at the inlet of the draft tube. It is found that the increasing tail water level affects the inlet boundary condition of the draft tube, the flow rate through the turbine, and draft tube. Thus, head recovery, efficiency and the possibility of cavitation phenomena decreases. However, the head loss increases, and the flow rate through the turbine and draft tube decrNumerical simulations of the flow in the elbow draft tube of a Kaplan turbine were carried out in order to elucidate the effects of tail water level on draft tube performance and flow stability. The influence of the tail water level is explored considering the correct boundary condition at the inlet of the draft tube. It is found that the increasing tail water level affects the inlet boundary condition of the draft tube, the flow rate through the turbine, and draft tube. Thus, head recovery, efficiency and the possibility of cavitation phenomena decreases. However, the head loss increases, and the flow rate through the turbine and draft tube decreasesIzvedene so bile numerične simulacije toka v kolenasti sesalni cevi kaplanove turbine z namenom preučitve vpliva spodnjega nivoja gladine vode na brezdimenzionalne karakteristike in na stabilnost toka v sesalni cevi. Vpliv nivoja spodnje vode je raziskan z upoštevanjem pravilnih robnih pogojev na vstopu. Ugotovljeno je bilo, da naraščanje spodnjega nivo vode vpliva na pretok skozi turbino in posledično na vstopni robni pogoj sesalne cevi. Posledično se izkoristek in verjetnost nastanka kavitacije zmanjša. Na drugi strani se hidravlične izgube povečajo, pretok skozi turbino in sesalno cev pa se zmanjšaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Mariboru, Fakulteta za energetiko