35 KB628 KB46 KB199920252005Bachert, RudolfDular, MatevžStoffel, BerndŠirok, Braneštevilka:115 straniletnik:51str. 13-27ISSN:0039-2480COBISSID:8034587URN:URN:NBN:SI:doc-HGS3WVKPenslAssociation of Mechanical Engineers and Technicians of Slovenia et al.Zveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikdinamika tekočinkavitacijametoda PIV-LIFvizualizacijaČasovno odvisna simulacija, vizualizacija in meritve kavitacije z metodo PIV-LIF na različnih osamljenih profilih| Transient simulation, visualization and PIV-LIF measurements of the cavitation on different hydrofoil configurations|This paper concerns a numerical and experimental study of cavitating flow around different single hydrofoils. The program package Fluent was used to calculate the unsteady flow, and the homogeneous flow principle was used to describe two-phase flow. The cavitation model based on a simplified Rayleigh-Plesset equation for bubble dynamics, was used to describe the appearance and collapse of a cavitation cloud. A 3D transient simulation of cavitating flow under different conditions for two hydrofoils was made. Images of the vapour structures under different cavitation conditions for the two hydrofoils were acquired. A PIV-LIF method was used to obtain the velocity field inside and outside the vapour cavity. Measurements of the cavitation cloud shedding frequencies were made. Numerically predicted distributions of the water vapour and the velocity field were compared with experimental results. The experimentally determined and numerically predicted mean cavity structure lengths along the hydrofoil were compared. Also, a comparison between the numerically predicted and the experimental cavitation cloud shedding frequencies was made. In all cases a good correlation between the experimental results and the numerical simulations was found. The simulation was also able to correctly predict the formation of typical "horseshoe" cavitation structuresPrispevek obravnava numerično in preizkusno studijo kavitirajočega toka okrog različnih osamljenih profilov. Za simulacijo neustaljenega toka je bil uporabljen programski paket Fluent. Dvofazni tok smo opisali z vpeljavo homogenega toka mešanice. Za popis nastanka in kolapsa kavitacijskega oblaka je bil uporabljen kavitacijski model, utemeljen na poenostavljeni Rayleigh-Plessetovi enačbi dinamike mehurčka. Narejene so bile trirazsežne simulacije kavitirajočega toka v različnih razmerah za dva osamljena profila. Za dva profila smo posneli slike kavitacijskih struktur v različnih razmerah. Za doloeitev hitrostnega polja zunaj in znotraj kavitacijskega oblaka smo uporabili metodo PIV-LIF. Izmerili smo frekvence trganja kavitacijskega oblaka. Numerieno napovedane porazdelitve deleza pare in hitrostnega polja smo primerjali s preizkusnimi rezultati. Narejena je bila primerjava s preizkusi doloeenih in numerieno napovedanih povpreenih dolzin kavitacijske strukture vzdolz profila. Primerjali smo tudi numerieno napovedane in s preizkusi doloeene frekvence trganja kavitacijskega oblaka. V vseh primerih smo dobili dobro ujemanje med rezultati preizkusov in simulacij. Poleg tega je simulacija pravilno napovedala nastanek značilne podkvaste kavitacijske struktureTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo