Browsing NTNU Open by Author "Pettersen, Bjørnar"

Now showing items 41-60 of 63

    • Numerical Studies of Viscous Flow Around Step Cylinders 

      Tian, Cai (Doctoral theses at NTNU;2021:122, Doctoral thesis, 2021)
      A step cylinder consists of a small diameter cylinder (d) attached coaxially to a large diameter cylinder (D). Structures with a similar shape as the step cylinder have been extensively used in many marine engineering ap- ...

    • Numerical studies of viscous flow around straight and curved tandem cylinders 

      Aasland, Tale Egeberg (Doctoral theses at NTNU;2024:81, Doctoral thesis, 2024)
      The physics of flow around straight and curved cylinders in tandem is investigated by means of direct numerical simulations (DNS), for transitional and turbulent flow regimes. For straight tandem cylinders in the reattachment ...

    • Numerisk simulering av en viskøs strømning rundt en krum sylinder i tverrstrøm 

      Mortensen, Olav Egaas (Master thesis, 2019)
      Denne masteravhandlingen presenterer numeriske undersøkelser av den tredimensjonale viskøse strømningen rundt en rett sirkulær sylinder og en krum sirkulær sylinder i tverrstrøm. Simuleringer har blitt utarbeidet i ...

    • Numerisk Simulering av strømning rundt en kurvet sylinder med varierende diameter 

      Ramsvik, Emil Severin (Master thesis, 2019)
      I denne masteroppgaven utforskes strømning rundt en konkav buet sylinder med en endring i diameter. Studien bruker direkte numerisk simulering for å løse Navier-Stokes ligningene uten bruk av turbulensmodellering. Fokuset ...

    • On the Effect of Boundary Conditions on the Flow around a Cylinder in a Channel 

      Strandenes, Håkon; Canabes, José Patricio Gallardo; Pettersen, Bjørnar; Andersson, Helge Ingolf (Chapter, 2015)
      In this paper, the incompressible external flow around an offshore drilling riser with fairings at Reynolds number 5000 is used to study the effects of varying boundary conditions in numerical simulations. We use a direct ...

    • Onset and Progression of Vortical Structures for a Surface Combatant at Drift Angles 0, 10 and 20 Degrees 

      Egeberg, Tale Fjell (Master thesis, 2013)
      The onset on progression of vortical structures of the ship model DTMB 5512 (geosym of DTMB5415) has been examined for drift angles -1, 10 and 20 degrees, by means of tomographic particle image velocimetry. The drift angle ...

    • Parametrisation of aquatic vegetation in hydraulic and coastal research: The importance of plant biomechanics in the hydrodynamics of vegetated flows 

      Henry, Pierre-Yves (Doctoral thesis at NTNU;2016:138, Doctoral thesis, 2016)
      Understanding the complexity of the interactions between aquatic biological systems and their physical environment is a critical condition for the sustainable management of aquatic environments. In such ecosystems, aquatic ...

    • Recent Developments and New Results on The Flow Around an Inclined 6:1 Prolate Spheroid 

      Strandenes, Håkon; Jiang, Fengjian; Pettersen, Bjørnar; Andersson, Helge Ingolf (Chapter, 2017)
      In the light of new computational resources and improved simulation tools we present new simulations of the flow around an inclined 6:1 prolate spheroid. We present the development of the flow from the symmetric and laminar ...

    • Revisiting the reattachment regime: a closer look at tandem cylinder flow at Re=10000 

      Aasland, Tale Egeberg; Pettersen, Bjørnar; Andersson, Helge Ingolf; Jiang, Fengjian (Peer reviewed; Journal article, 2022)
      Tandem cylinder flow comprises several different flow regimes. Within the reattachment regime, the development of the gap shear layers is of utmost importance to the flow, but has received little attention so far. Through ...

    • Simulation of Flow Around an Oil Boom 

      Bjørvik, Henning (Master thesis, 2015)
      The interFoam solver is used in this thesis. This solver applies the VOF method to trace the interface between two fluids. This method and the interFoam solver is thoroughly discussed in this thesis. A convergence study ...

    • Simulation of Viscous Flow Around a Circular Cylinder with OpenFOAM 

      Finserås, Live Reiten (Master thesis, 2013)
      Flow around a circular cylinder has been extensively studied, both numerically and experimentally, for a number of years. With the increase in flow-structure interactions around marine structures such as platform legs/columns, ...

    • Simulation of viscous Flow around a circular Cylinder with STAR-CCM+ 

      Thingbø, Sunniva Selstad (Master thesis, 2013)
      In this thesis, three-dimensional modelling of the flow around a circular cylinder isaccomplished. Two cases are considered. The first (Case 1) is a cylinder in steady,uniform current subjected to Reynolds number 3900. The ...

    • The Effect of Waves on Marine Propellers and Propulsion 

      Taskar, Bhushan (Doctoral theses at NTNU;2017:106, Doctoral thesis, 2017)
      Ship design is evolving around ever-increasing market demands in quest of competitive and cost-effective solutions. The global increase of shipping activities has raised concerns regarding the environmental impact of sea ...

    • Turbulence Modelling of the Flow Around a Prolate Spheorid 

      Larssen, Henrik Stumberg (Master thesis, 2018)
      In numerous engineering disciplines, including naval and offshore engineering, the accurate prediction of turbulent flows is essential for cost-efficient and safe designs. For industrial applications, the turbulence must ...

    • Turbulent flow simulations at higher Reynolds numbers 

      Strandenes, Håkon (Doctoral theses at NTNU;2019:52, Doctoral thesis, 2019)
      This thesis presents recent advancements in direct numerical simulations of bluff body wake flows. The flow around a circular cylinder without and with special fairings have been studied, and the effect of boundary conditions ...

    • Turbulent wake behind a concave curved cylinder 

      Jiang, Fengjian; Pettersen, Bjørnar; Andersson, Helge Ingolf (Journal article; Peer reviewed, 2019)
      We present a detailed study of the turbulent wake behind a quarter-of-ring curved cylinder at Reynolds number Re = 3900 (based on cylinder diamter and incoming ow velocity), by means of Direct Numerical Simulation (DNS). ...

    • Viscous Flow Around Finite Lenght Circular Cylinder 

      Levold, Pål (Master thesis, 2012)
      Viscous flow around circular cylinders is a classical research topic in fluid dynamics with a vast amount of practical applications in the field of offshore marine technology. In the flow around cylinders of finite length, ...

    • Viscous Flow Around Inclined Circular Cylinder 

      Cai, Zhisong (Master thesis, 2017)
      Circular cylinder is of vital importance in the marine industry. The goal of this thesis is to study the physical phenomenon around the inclined circular cylinder as well as the forces acting on it. The study is mainly ...

    • Vortex dislocation mechanisms in the near wake of a step cylinder 

      Tian, Cai; Jiang, Fengjian; Pettersen, Bjørnar; Andersson, Helge Ingolf (Peer reviewed; Journal article, 2020)
      Vortex interactions behind step cylinders with diameter ratio D/d = 2 and 2.4 at Reynolds number ( ReD ) 150 were investigated by directly solving the three-dimensional Navier–Stokes equations. In accordance with previous ...

    • Vortex system around a step cylinder in a turbulent flow field 

      Tian, Cai; Jiang, Fengjian; Pettersen, Bjørnar; Andersson, Helge Ingolf (Peer reviewed; Journal article, 2021)
      The vortex system around the step surface of a step cylinder with a diameter ratio D/d=2 at Reynolds number (ReD) 3900 was investigated by directly solving the three-dimensional Navier–Stokes equations. Formation mechanisms ...