수정된 밀도함수법을 이용한 Spilling Breaker의 수치시뮬레이션
Numerical Simulation of Spilling Breaker using the Modified Marker-density Method
1
조회
0
다운로드
2
인용
0
참고문헌
키워드
초록
Numerical simulations for the flows containing free surface remain difficult problems because the drastic differences of physical properties of water and air, The difference of densities makes the solution instable in particular. For the stabilities of the solutions, the most typical methods to simulate free surface flows, such as Volume Of Fluid(VOF) and Level-Set(LS) methods, impose transient zones where the physical prosperities are continuously distributed. The thickness of the transient zone is the source of the numerical errors. The other side, marker-density method does not use such a transient zone. In the traditional marker-density method, however, the air velocities of free surface cells are extrapolated from the water velocity, and the pressures on the free surface are extrapolated from the air pressures for the stability of the solution. In this study, the marker-density method is modified for the decrease of such numerical errors. That is, the pressure on the free surface is determined to coincide with the pressure gradient terms of the governing equations, and the velocity of free surface cells are calculated with the governing equations. Two-dimensional steady spilling breakers behind of a submersed hydrofoil and three-dimensional spilling breaker near a wedge shaped ship model are simulated using INHAWAVE-II including the modified marker-density(MMD) method. The results are compared with the results of Fluent V6.3 including VOF method and several published research results.
Abstract
Numerical simulations for the flows containing free surface remain difficult problems because the drastic differences of physical properties of water and air, The difference of densities makes the solution instable in particular. For the stabilities of the solutions, the most typical methods to simulate free surface flows, such as Volume Of Fluid(VOF) and Level-Set(LS) methods, impose transient zones where the physical prosperities are continuously distributed. The thickness of the transient zone is the source of the numerical errors. The other side, marker-density method does not use such a transient zone. In the traditional marker-density method, however, the air velocities of free surface cells are extrapolated from the water velocity, and the pressures on the free surface are extrapolated from the air pressures for the stability of the solution. In this study, the marker-density method is modified for the decrease of such numerical errors. That is, the pressure on the free surface is determined to coincide with the pressure gradient terms of the governing equations, and the velocity of free surface cells are calculated with the governing equations. Two-dimensional steady spilling breakers behind of a submersed hydrofoil and three-dimensional spilling breaker near a wedge shaped ship model are simulated using INHAWAVE-II including the modified marker-density(MMD) method. The results are compared with the results of Fluent V6.3 including VOF method and several published research results.
참고문헌 (20)
- Study on Separation of Ship Resistance Components, "Baba", Mitsubishi Heavy industry Technical Bulletin, 59~ (1969)
- Duncan, J. H., "The Breaking and Non-Breaking Wave Resistance of a Two-Dimensional Hydrofoil", Journal of Fluid Mechanics, 126, pp.507~520 (1983)
- Duncan, J. H., "Spilling Breakers", Annual Review of Fluid Mechanics, 33, pp.519~547 (2001)
- Fergizer & Peric, "Computational Methods for Fluids Dynamics" (2002), Springer
- Hirt, C.W., "Volume of Fluid(VOF)method for the dynamics of free boundaries", Journal Computational Physics, 39, pp.201~225 (1981)
- Hu, C, "A CIP-Based Method for Numerical Simulations of Violent Free-Surface Flows", Journal Marine Science and Technology, 9, pp.143~157 (2004)
- 이영길, "밀도함수법을 이용한 2차원 슬로싱 현상의 수치시뮬레이션", 대한조선학회 논문집, 46(6), pp.650~658 (2009), 대한조선학회
- Lee, Y.G., "The Marker-Density Method in Cartesian Grids Applied to Nonlinear Ship Waves", Computers and Fluids, 63(30), pp.57~69 (2012)
- Lee, Y.G., "A Numerical Simulation Method for Free Surface Flows Near a Two-Dimensional Moving Body in Fixed Rectangular Grid System", Ocean Engineering, 59, pp.285~295 (2013)
- Lopez, J., "An Improved PlIC-VOF Method for Tracking Thin Fluid Structures in Imcompressible Two-Phase flows", Journal Computational Physiscs, 208, pp.51~74 (2005)
- Muscari, R., "A model of spilling breaking in RANS simulation", Proceedings of the 12th ISOPE Conference, pp.161~166 (2002)
- Muscari, R., "A numerical study of breaking waves", Proceedings of Symposium on Reduction of Military Vechicle Acquisition Time and Cost through Advanced Modelling and Virtual Simulation, pp.36-1~36-6 (2002)
- Muscari, R, "A spilling breaking model for wave flows around ships", Proceedings of the 13th ISOPE Conference, pp.315~319 (2003)
- Olivieri, A., "Scars and Vortices Induced by Ship Bow and Shoulder Wave Breaking", Journal of Fluids Engineering, 129, pp.1445~1159 (2007)
- Osher, S., "Fronts Propagation with Curvature-Dependent Speed : Alogrithms Bases on Hamiltion–Jacobi Formulations", Journal of Computational Physics, 79, pp.12~49 (1988)
- Park, J,C, "Fully Non-Linear Free-Surface Simulations by a 3d viscous Numerical Wave Tank", International Journal Numerical Methods in Fluids, 29, pp.685~703 (1999)
- Scardovelli, R., "Direct Numerical Simulation of Free-Surface and Interfacial Flow", Annual Review of Fluid Mechanics, 31, pp.567~603 (1999)
- Tulin, M.P., "A Theory of Steady Breakers", Journal of Fluid Mechanics, 276, pp.1~20 (1986)
- Yu, K., "CFD Simulation of Wave-Current-Body Interactions Including Greenwater and Wet Deck Slamming", Computers & Fluids, 38, pp.970~980 (2009)
- Zhao, X, "Numerical and Experimental Study on a 2-D Floating Body under Extreme Wave Conditions", Applied Ocean Research, 35, pp.1~13 (2011)