Djelovanje vjetra na veliki kontejnerski brod

master's thesis

• Title (english): Wind effects on a large container ship
• Author: Bojan Gunjević
• Mentor: Hrvoje Kozmar (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2013-02-15, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U radu je postavljen i proveden model računalne simulacije strujanja vjetra oko velikog kontejnerskog broda s ciljem određivanja aerodinamičkih opterećenja za različite tipove obalnog terena i kuteve nastrujavanja vjetra na brod. Karakteristike strujanja vjetra odgovaraju atmosferskom graničnom sloju. Proračun je proveden računalnim paketom koji se temelji na rješavanju osrednjenih Navier-Stokesovih jednadžbi uz primjenu k-ε modela turbulencije. Prije simulacije opterećenja vjetrom na kontejnerski brod ispitano je strujanje vjetra kroz praznu računalnu domenu bez broda da bi se ustanovile promjene profila brzine, kinetičke energije turbulencije i disipacije kinetičke energije turbulencije od ulaza u računalnu domene do pozicije na kojoj se nalazi brod. Postavljena računalna simulacija je validirana usporedbom postignutih opterećenja vjetrom na kontejnerski brod s analitičkim izrazima izvedenim na temelju eksperimenata u zračnom tunelu. Zabilježene razlike u rezultatima su djelomično uslijed različitih karakteristika nastrujavanja vjetra na brod, pri čemu uvjeti nastrujavanja u ovom radu odgovaraju realnim uvjetima u prirodi.

Abstract (english)

Computational model has been developed to simulate wind loads on a large container ship for different coastal terrains and wind incidence angles. Wind characteristics were adopted to correspond to the atmospheric boundary layer flow. Computations were performed using the software package based on solving Reynolds-Averaged-Navier-Stokes equations using the k-ε turbulence model. Prior to testing wind loading of a large container ship, wind flow through an empty computational domain without the ship was investigated in order to determine changes in the velocity, turbulent kinetic energy, and dissipation of turbulent kinetic energy profiles from inlet to the ship position. For all coastal terrain types, an increase in velocity and a decrease in turbulent kinetic energy between an inlet and the ship position are observed, while differences in dissipation of turbulent kinetic energy profiles are negligible. Differences in coastal terrain type influence drag coefficients. In particular, drag coefficients CD and CL increase with an increase in coastal urbanization, while moment coefficients CM are nearly the same for all terrain types. As the wind incidence angle increases, absolute values for CD decrease and absolute values for CL increase, while maximum values for CM are observed at 45° and 90° wind incidence angles. Computational model developed in this study has been validated against analytical expressions based on wind-tunnel experiments. Differences in computational and analytical results are possibly due to different inflow conditions in those two approaches, where wind characteristics in this study correspond to realistic atmospheric conditions.

• Keywords: Aerodinamika kontejnerskog broda; atmosferski granični sloj; računalna dinamika fluida (CDF); k-ε model turbulencije
• Keywords (english): Container ship aerodynamics; Atmospheric boundary layer; Computational fluid dynamics (CFD); k-ε turbulence model
• Language: croatian
• URN:NBN: urn:nbn:hr:235:717128
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2019-05-27 10:01:38