scholarly journals The effects of free surface and end cell on flow around a finite circular cylinder with low aspect ratio

2015 ◽  
Vol 21 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Haruki Fukuoka ◽  
Shinichiro Hirabayashi ◽  
Hideyuki Suzuki
Keyword(s):  
Free Surface ◽  
Aspect Ratio ◽  
Circular Cylinder ◽  
Low Aspect Ratio

CFD Calculations for Free-Surface-Piercing Low Aspect Ratio Circular Cylinder With Solution Verification and Comparison With Experiments

2013 ◽  
Author(s):  
Guilherme F. Rosetti ◽  
Guilherme Vaz ◽  
Martin Hoekstra ◽  
Rodolfo T. Gonçalves ◽  
André L. C. Fujarra
Keyword(s):  
Free Surface ◽  
Aspect Ratio ◽  
Circular Cylinder ◽  
Phase Interface ◽  
Surface Effects ◽  
Surface Flow ◽  
Small Scale ◽  
Two Phase ◽  
End Effects ◽  
Low Aspect Ratio

The flow around free-surface piercing, low aspect-ratio circular cylinder is investigated by means of unsteady Reynolds averaged Navier-Stokes (URANS) calculations together with verification procedures and comparison with small-scale experimental and Particle Image Velocimetry results. A two-phase interface capturing model is used to handle the free-surface flow, together with k-ω SST turbulence model. We investigate physical and modeling aspects of this problem in order to gain more knowledge about the interaction of free-surface and free-end effects so that this mechanism is better understood and taken into account when modeling the problem in engineering-applied situations, such as the vortex induced motion of spars, tension-leg platforms and semi-submersibles. The case herein presented is a captive, low aspect-ratio cylinder (L/D = 2.0) with flow velocity corresponding to Reynolds and Froude numbers (both based on diameter) of Re = 4.3 × 104 and FnD = 0.31, respectively. We will show that appreciable free-surface effects are perceived on the flow, but with dominance of free-end effects, at least in terms of forces. Furthermore, we investigate different boundary conditions that would represent this free-surface problem to show that the separation of viscous and free-surface effects is not valid in this instance. Therefore, the interaction between viscous and free-surface effects is also tangentially investigated. In order to support our conclusions, we will show forces with uncertainty estimation and field variables obtained with different modeling strategies, unveiling physical and numerical aspects of this problem.

A simple example from flat-ship theory

1988 ◽  
Vol 189 ◽  
pp. 301-310 ◽  
Author(s):  
Susan Cole
Keyword(s):  
Exact Solution ◽  
Free Surface ◽  
Energy Balance ◽  
Aspect Ratio ◽  
Pressure Distribution ◽  
Wave Drag ◽  
Vortical Flow ◽  
Far Field ◽  
Low Aspect Ratio ◽  
Free Surface Waves

This paper describes the induced pressure distribution, free-surface waves, vortical flow and wave drag of an exact solution of low-aspect-ratio flat-ship theory. An energy balance is derived which relates the spray drag, the energy carried away by the far-field waves and the vortical flow to the total wave drag.

FREE-SURFACE EFFECTS ON HYDRODYNAMIC FORCES FOR HALF-SUBMERGED CIRCULAR CYLINDERS WITH LOW ASPECT RATIO

2019 ◽  
Author(s):  
Keigo Sakata ◽  
Shinichiro Hirabayashi ◽  
Yasuo Yoshimura ◽  
Hideyuki Suzuki ◽  
Rodolfo Gonçalves
Keyword(s):  
Free Surface ◽  
Aspect Ratio ◽  
Surface Effects ◽  
Hydrodynamic Forces ◽  
Circular Cylinders ◽  
Low Aspect Ratio

scholarly journals The effect of base column on vortex-induced vibration of a circular cylinder with low aspect ratio

2020 ◽  
Vol 196 ◽  
pp. 106822 ◽  
Author(s):  
Yuanchuan Liu ◽  
Fushun Liu ◽  
Enhao Wang ◽  
Qing Xiao ◽  
Liang Li
Keyword(s):  
Aspect Ratio ◽  
Circular Cylinder ◽  
Vortex Induced Vibration ◽  
Low Aspect Ratio
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