Measurement of Turbulence Properties at the Time of Flow Reversal Under High Wave Conditions in Hujeong Beach
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The temporal distribution of the turbulence kinetic energy (TKE) and the vertical component of Reynolds stresses ( ) was measured during one wave period under high wave energy conditions. The wave data were obtained at Hujeong Beach in the east coast of Korea at January 14~18 of 2017 when an extratropical cyclone was developed in the East Sea. Among the whole thousands of waves measured during the period, hundreds of regular waves that had with similar pattern were selected for the analysis in order to give three representing mean wave patterns using the ensemble average technique. The turbulence properties were then estimated based on the selected wave data. It is interesting to find out that has one clear peak near the time of flow reversal while TKE has two peaks at the corresponding times of maximum cross-shore velocity magnitudes. The distinguished pattern of Reynolds stress indicates that vertical fluxes of such properties as suspended sediments may be enhanced at the time when the horizontal flow direction is reversed to disturb the flows, supporting the turbulence convection process proposed by Nielsen (1992). The characteristic patterns of turbulence properties are examined using the CADMAS-SURF Reynolds-Averaged Navier-Stokes (RANS) model. Although the model can reasonably simulate the distribution of TKE pattern, it fails to produce the peak at the time of flow reversal, which indicates that the application of RANS model is limited in the prediction of some turbulence properties such as Reynolds stresses.
Abstract
The temporal distribution of the turbulence kinetic energy (TKE) and the vertical component of Reynolds stresses ( ) was measured during one wave period under high wave energy conditions. The wave data were obtained at Hujeong Beach in the east coast of Korea at January 14~18 of 2017 when an extratropical cyclone was developed in the East Sea. Among the whole thousands of waves measured during the period, hundreds of regular waves that had with similar pattern were selected for the analysis in order to give three representing mean wave patterns using the ensemble average technique. The turbulence properties were then estimated based on the selected wave data. It is interesting to find out that has one clear peak near the time of flow reversal while TKE has two peaks at the corresponding times of maximum cross-shore velocity magnitudes. The distinguished pattern of Reynolds stress indicates that vertical fluxes of such properties as suspended sediments may be enhanced at the time when the horizontal flow direction is reversed to disturb the flows, supporting the turbulence convection process proposed by Nielsen (1992). The characteristic patterns of turbulence properties are examined using the CADMAS-SURF Reynolds-Averaged Navier-Stokes (RANS) model. Although the model can reasonably simulate the distribution of TKE pattern, it fails to produce the peak at the time of flow reversal, which indicates that the application of RANS model is limited in the prediction of some turbulence properties such as Reynolds stresses.
참고문헌 (20)
- Amoudry, L. O., "Toward representing wave-induced sediment suspension over sand ripples in RANS models", J. Geophys. Res, 118(1), pp.658~673 (2013)
- Boussinesq, J., "Essai sur la théorie des eaux courantes", Mémoires présentés par divers savants à l'Académie des Sciences, 23(1), pp.1~680 (1877)
- Chang, Y. S., "Suspended sediment and hydrodynamics above mildly sloped large wave ripples", J. Geophys. Res, 109(C7) (2004)
- 장연식, "Sensitivity of Suspension Pattern of Numerically Simulated Sediments to Oscillating Periods of Channel Flows over a Rippled Bed", KSCE Journal of Civil Engineering, 21(5), pp.1503~1515 (2017), 대한토목학회[DOI]
- 장연식, "Suspension of Sediment Particles over a Ripple due to Turbulent Convection under Unsteady Flow Conditions", Ocean Science Journal, 51(1), pp.127~135 (2016), 한국해양과학기술원[DOI]
- Chang, Y. S., "Modeling unsteady turbulent flows over ripples: Raynolds-averaged navier- stokes equations (rans) versus large-eddy simulation (les).", J. Geophys. Res., 109(C9) (2004)
- Chang, Y.S., "Turbulent convection of suspended sediments due to flow reversal", J. Geophys. Res, 111(C07001) (2006)
- Hieu, P.D., "Verification of a VOF-based two-phase flow model for wave breaking and wave-structure interactions", Ocean Engineering, 33, pp.1565~1588 (2006)
- Hirt, C.W., "Volume of fluid(VOF) method for the dynamics of free boundaries", J. of Computational Physics, 39, pp.201~225 (1981)
- 정원무, "동해안에서의 이상 고파", 한국해안·해양공학회논문집, 19(4), pp.295~302 (2007), 한국해안,해양공학회
- 정원무, "장기실측 파랑자료 분석을 통한 동해안 폭풍파 출현 추세", 한국해안·해양공학회논문집, 28(2), pp.109~115 (2016), 한국해안,해양공학회
- Launder, B.E, "The numerical computation of turbulent flows", Computer Methods in Applied Mechanics and Engineering, 3(2), pp.269~289 (1974)
- 남인식, "투과성 해안구조물의 소상파 및 내부수위변동에 관한 수치모델링", 한국해양공학회지, 16(5), pp.34~40 (2002), 한국해양공학회
- Nielsen, P., "Coastal bottom boundary layers and sediment transport. Vol. 4" (1992), World Scientific
- Research and development of numerical wave channel (CADMAS-SURF), "PHRI", CDIT Library, ~, pp.CDIT Library, Vol. 12 (2001)
- Rodi, W., "Turbulence modeling and simulation in hydraulics:a historical review", Hydraulic Eng, 143(5), pp.1~20 (2017)
- Schmitt, F. G., "About Boussinesq’s turbulent viscosity hypothesis: historical remarks and a direct evaluation of its validity", Comptes Rendus Mécanique, 335(9-10), pp.617~627 (2007)
- Scotti, A., "Numerical simulation of pulsating turbulent channel", Phys. Fluids, 13(5), pp.1367~1384 (2001)
- Wilcox, C. D., "Turbulence Modeling for CFD" (1998), DCW Industries
- 윤한삼, "투과성 해안구조물의 Wave Run-up에 대한 CADMAS-SURF의 적용", 한국해양공학회지, 19(4), pp.49~55 (2005), 한국해양공학회