Numerical simulation of viscous flow around bulk carrier model

U ovom radu provedene su numeričke simulacije pokusa otpora modela Japan Bulk Carrier (JBC) broda primjenom računalne dinamike fluida (RDF) kako bi se odredio ukupni otpor, uron/izron i trim modela broda. Dan je pregled literature vezane uz mogućnosti primjene RDF-a u području brodske hidrodinamike. Za provođenje numeričkih simulacija korišten je komercijalni programski paket STAR-CCM+. Numeričke simulacije provedene su na temelju modela nestacionarnog trodimenzijskog viskoznog strujanja fluida sa slobodnom površinom, primjenom Reynoldsovih osrednjenih Navier-Stokesovih (eng. Reynolds Averaged Navier-Stokes, RANS) jednadžbi. Primijenjen je k – ε model turbulencije i metoda udjela fluida u volumenu (eng. Volume of Fluid, VOF) za opis gibanja dvofaznog medija. Ispitan je utjecaj gustoće mreže te vremenskog koraka na rezultate ukupnog otpora za jedan Froudeov broj. Koeficijent ukupnog otpora modela broda dobiven numeričkim simulacijama uspoređen je s eksperimentalnim podacima dostupnim u literaturi. Pokazano je kako RDF omogućuje zadovoljavajuće rezultate u procjeni ukupnog otpora modela broda.Within this study, numerical simulations of resistance test for a ship model of Japan Bulk Carrier (JBC) are performed using Computional Fluid Dynamics (CFD) to determine total resistance, trim and sinkage of a ship model. The possibilities of CFD application in the field of ship hydrodynamics are presented within the literature review. Numerical simulations are performed within commercial software package STAR CCM+, based on the model of unsteady three-dimensional viscous flow with free surface utilizing Reynolds averaged Navier-Stokes (RANS) equations. The k – ε turbulance model is used and Volume of Fluid (VOF) method is applied for the motion description of two-phase media. The influence of the grid density and time step on the results of the total resistance is anlysed for one Froude number. The total resistance coefficient obtained by numerical simulations is compared with the experimental data available in the literature. It has been demonstrated that CFD provides results of satisfactory accuracy in the estimation of the total resistance of a ship model