Evaluation of URANS Solvers for Cylindrical Structures in Tidal Flow

Research output: Contribution to conferencePaper

Abstract

In tidal conditions Reynolds numbers (Re) around cylindrical structures can range from zero up to supercritical values, with vortex shedding causing significant vibration and undesirable forces throughout. Two realistic options for investigating these phenomena in an engineering environment include the Navier-Stokes solvers ANSYS® CFX-13.0 and OpenFOAM®. In this study both are considered at Reynolds numbers ranging from 40 to 106, representing a full range of tidal conditions. A 2D Unsteady Reynolds Averaged Naver-Stokes (URANS) approach is developed in an attempt to balance the speed and accuracy of the solutions. To eliminate mesh dependency, low-Re boundary layer meshing is employed along with Courant controlled time stepping.

Numerical results obtained from both solvers are presented for lift coefficient, drag coefficient and Strouhal number. Values from both solvers are compared to literary sources and examined for accuracy. Given that the turbulence for much of the Reynolds number region explored is known to be highly three dimensional, both codes offer a mix of good and poor results depending on parameters. Overall low and subcritical Re values are modelled with success by OpenFOAM, while force terms in upper critical and supercritical flows are better predicted by CFX.

Conference

ConferenceThe 22nd International Ocean and Polar Engineering Conference (ISOPE 2012)
CountryGreece
CityRhodes
Period17/06/1223/06/12

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Reynolds number
Strouhal number
Vortex shedding
Drag coefficient
Boundary layers
Turbulence

Cite this

Stringer, R., & Zang, J. (2012). Evaluation of URANS Solvers for Cylindrical Structures in Tidal Flow. Paper presented at The 22nd International Ocean and Polar Engineering Conference (ISOPE 2012), Rhodes, Greece.

Evaluation of URANS Solvers for Cylindrical Structures in Tidal Flow. / Stringer, Robert; Zang, Jun.

2012. Paper presented at The 22nd International Ocean and Polar Engineering Conference (ISOPE 2012), Rhodes, Greece.

Research output: Contribution to conferencePaper

Stringer, R & Zang, J 2012, 'Evaluation of URANS Solvers for Cylindrical Structures in Tidal Flow' Paper presented at The 22nd International Ocean and Polar Engineering Conference (ISOPE 2012), Rhodes, Greece, 17/06/12 - 23/06/12, .
Stringer R, Zang J. Evaluation of URANS Solvers for Cylindrical Structures in Tidal Flow. 2012. Paper presented at The 22nd International Ocean and Polar Engineering Conference (ISOPE 2012), Rhodes, Greece.
Stringer, Robert ; Zang, Jun. / Evaluation of URANS Solvers for Cylindrical Structures in Tidal Flow. Paper presented at The 22nd International Ocean and Polar Engineering Conference (ISOPE 2012), Rhodes, Greece.
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AU - Zang,Jun

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