Istraživanje utjecaja ljuljnih kobilica na ukupni otpor broda

undergraduate thesis

• Title (english): An investigation into the effect of bilge keels on the total resistance of a ship
• Author: Frano Badrov
• Mentor: Nastia Degiuli (mentor)
• Mentor: Ivana Martić (mentor)
• Committee member: Ivan Ćatipović (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-03-04, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Shipbuilding; Hydromechanics of Floating and Maritime Structures

Abstract

U ovom radu provedene su numeričke simulacije pokusa otpora INSEAN 2340 modela broda američke ratne mornarice za goli trup te trup modela broda s privjescima odnosno ljuljnim kobilicama. Numeričke simulacije provedene su primjenom komercijalnog programskog paketa za računalnu dinamiku fluida (RDF) STAR-CCM+. Unutar numeričkih simulacija primijenjen je matematički model nestacionarnog trodimenzijskog viskoznog strujanja fluida sa slobodnom površinom na temelju Reynoldsovih osrednjenih Navier – Stokesovih jednadžbi (eng. Reynolds Averaged Navier -Stokes, RANS). Primijenjen je k - ω model turbulencije i metoda udjela fluida u volumenu (eng. Volume of Fluid, VOF) za praćenje i lociranje slobodne površine. Proveden je postupak verifikacije te je određena numerička nesigurnost rezultata dobivenih primjenom različite gustoće mreže i vremenskog koraka. Dobiveni numerički rezultati za koeficijent ukupnog otpora, uron/izron i trim uspoređeni su s eksperimentalno dobivenim podacima za goli trup. Numerička simulacija pokusa otpora provedena je i za model broda s ljuljnim kobilicama kako bi se odredilo povećanje ukupnog otpora uslijed ljuljnih kobilica te analiziralo strujanje oko njih.

Abstract (english)

In this study numerical simulations of resistance test for the INSEAN 2340 US Navy surface combatant ship model are carried out for bare hull and hull with bilge keels. Numerical simulations are performed within commercial software package for Computational Fluid Dynamics (CFD) STAR-CCM+. Within numerical simulations, a mathematical model of unsteady three-dimensional viscous flow with free surface based on Reynolds Averaged Navier-Stokes (RANS) equations is applied along with the k - ω turbulence model. The Volume of Fluid (VOF) method is used for tracking and locating the free surface. The verification study is performed and the numerical uncertainty of the results obtained using different grid densities and the time step is determined. The obtained numerical results for the total resistance coefficient, sinkage and trim are compared with the experimentally obtained data for the bare hull. Additionally, numerical simulation of the resistance test is performed for the ship model with bilge keels to determine the increase in the total resistance due to bilge keels and to analyze the flow around them.

• Keywords: računalna dinamika fluida; metoda udjela fluida u volumenu; k - ω model turbulencije; Reynoldsove osrednjene Navier – Stokesove jednadžbe; pokus otpora; ljuljne kobilice
• Keywords (english): Computional Fluid Dynamics; Volume of Fluid method; k - ω turbulence model; Reynolds Averaged Navier-Stokes equations; resistance test; bilge keels
• Language: croatian
• URN:NBN: urn:nbn:hr:235:141360
• Study programme: Title: Naval Architecture; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka brodogradnje (sveučilišni prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka brodogradnje)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-03-02 09:13:23