Modelling of flow around hexagonal and textured cylinders

Karampour, Hassan; Wu, Ziying; Lefebure, Julien; Jeng, Dong‐Sheng; Etemad‐Shahidi, Amir; Simpson, Benjamin

doi:10.1680/jencm.17.00021

Cited by 7 publications

(6 citation statements)

References 46 publications

(46 reference statements)

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“…The comparison of lift and drag coefficients values is presented in table 2 based on Reynolds number. It is noticed that corner-oriented pentagonal obstacle having larger drag coefficient value than face-oriented pentagonal obstacle, this fact is in good agreement with existing findings in [6]. Also, it is known that the obstacle owns larger value of drag, produces relatively less pressure in the downstream and vice versa.…”

Section: Figure -4: Comparison Of Drag Coefficient Values For Corner and Face -Oriented Obstaclesupporting

confidence: 89%

“…In [6], researchers investigated the different shaped cylinders includes; circular, square, corner-oriented hexagonal and face-oriented hexagonal. Their study primarily based on the comparison of drag coefficient determined at moderate Re = 200, it is beheld that the value of drag coefficient of faceoriented hexagonal is comparatively smaller than the drag coefficient found in the case of corner-oriented hexagonal cylinder.…”

Section: Introductionmentioning

confidence: 99%

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Numerical Analysis of Unsteady Laminar Flow past a Pentagonal Obstacle

2021

IJATCSE

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The current article dispenses the numerical investigation of a two dimensional unsteady laminar flow of incompressible fluid passing a regular pentagonal obstacle in an open rectangular channel. The centre of attention of this work is the comparison of drag coefficients estimated for two distinct cases based on the orientation of face and corner of an obstacle against the flow direction. The numerical results shows that the corner – oriented obstacle bring about 42% larger value of drag coefficient at Re = 500 than face – oriented obstacle. The substantial growth in the expanse of vortex behind obstacle (presented as a function of fluid inertia 25 < Re < 500) is analyzed through the contours and streamline patterns of velocity field. The two eddies in the downstream become entirely unsymmetrical at Re = 500 for both the cases, whereas; the flow separation phenomena occurs a bit earlier in the face – oriented case at Re = 250. Two dimensional Pressure – Based – Segregated solver is employed to model the governing equations written in velocity and pressure fields. The numerical simulations of unsteady flow are presented for 50 seconds time frame with time step 0.01 by using one of the best available commercial based Computational Fluid Dynamics (CFD) software, ANSYS 15.0.

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Section: Figure -4: Comparison Of Drag Coefficient Values For Corner and Face -Oriented Obstaclesupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Unsteady Laminar Flow past a Pentagonal Obstacle

2021

IJATCSE

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“…Recently Mina et al (2020) developed fragility curves that account for the interaction between buckling and earthquakes and Triantafyllaki et al (2020) performed 3D numerical simulations of a partially embedded (unburied) pipeline in to assess its vulnerability to a fault rupture. Other authors (such as Karampour et al (2018Karampour et al ( , 2015, Alrzai and , Binazir et al (2019), Stephan et al (2016) and Piran at al. (2020) investigated the stability of subsea pipelines and pipe-in-pipe systems under hydrostatic, hydrodynamic, thermal and combined actions.…”

Section: Introductionmentioning

confidence: 96%

Soil Structure Interaction Effects on Stability of HP/HT Unburied Subsea Pipelines Using a Probabilistic-Based Approach

Forcellini

Mina

Karampour

2021

Preprint

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Soil structure interaction (SSI) may considerably affect the seismic vulnerability of subsea high pressure/high temperature (HP/HT) pipelines. Numerical simulations are herein proposed to study the effects of soil deformability on failure of an unburied pipeline with D/t = 20, laid on the seabed and resting on a sleeper. OpenSees is used to assess an earthquake scenario imposed on a laterally buckled pipeline by considering the effects of non-linear soil behaviour on the mechanisms that induce damage on the soil-pipeline system. Uncertainties in the case study were considered by applying a probabilistic-based approach and by developing analytical fragility curves that allow estimation of the probability of exceedance of the selected failure criteria.

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“…Unlike square cylinders, the vortex-induced vibrations of polygonal cylinders have been marginally studied in wind engineering such as in bridge decks Kawatani et al [42] or in marine structures such as bundled pipelines [43]. Limited studies are available on vortex-shedding from hexagonal cylinders [44][45][46]. This study aims to investigate the cross-flow VIV response of hexagonal cylinders with m * = 2 at Re = 1000.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Cross-Flow Vortex-Induced Vibration of Hexagonal Cylinders with Face and Corner Orientations at Low Reynolds Number

Piran

Karampour

Woodfield

2020

JMSE

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Vortex-induced vibrations (VIV) of hexagonal cylinders at Reynolds number of 1000 and mass ratio of 2 are studied numerically. In the numerical model, the Navier–Stokes equations are solved using finite volume method, and the fluid-structure interaction (FSI) is modelled using Arbitrary Lagrangian Eulerian (ALE) Scheme. The numerical model accounts for the cross-flow vibration of the cylinders, and is validated against published experimental and numerical results. In order to account for different angles of attack, the hexagonal cylinders are studied in the corner and face orientations. The results are compared with the published results of circular and square cylinders. Current results show that within the studied range of reduced velocities (up to 20), unlike circular and square cylinders, no lock-in response is observed in the hexagonal cylinders. The maximum normalized VIV amplitudes of the hexagonal cylinders are 0.45, and are significantly lower than those of circular and square cylinders. Vortex shedding regimes of the corner-oriented hexagons are mostly irregular. However, in the face-oriented hexagons, the shedding modes are more similar to the typical P + S and 2P modes.

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Modelling of flow around hexagonal and textured cylinders

Cited by 7 publications

References 46 publications

Numerical Analysis of Unsteady Laminar Flow past a Pentagonal Obstacle

Numerical Analysis of Unsteady Laminar Flow past a Pentagonal Obstacle

Soil Structure Interaction Effects on Stability of HP/HT Unburied Subsea Pipelines Using a Probabilistic-Based Approach

Numerical Simulation of Cross-Flow Vortex-Induced Vibration of Hexagonal Cylinders with Face and Corner Orientations at Low Reynolds Number

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