Two Open Boundary Conditions for Nonlinear Free Surface Flows

Fluid Flow ◽  
1991 ◽  
pp. 309-324
2020 ◽  
Vol 196 ◽  
pp. 106845 ◽  
Author(s):  
Xingye Ni ◽  
Weibing Feng ◽  
Shichang Huang ◽  
Xin Zhao ◽  
Xinwen Li

1999 ◽  
Vol 43 (01) ◽  
pp. 13-24
Author(s):  
M. Landrini ◽  
G. Grytøyr ◽  
O. M. Faltinsen

Fully nonlinear free-surface flows are numerically studied in the framework of the potential theory. The problem is formulated in terms of boundary integral equations which are solved by means of an arbitrary high-order boundary element method based on B-Spline representation of both the geometry and the fluid dynamic variables along the domain boundary. The solution is stepped forward in time either by following Lagrangian points attached to the free surface or by a less conventional scheme in which evolution equations for the B-Spline coefficients are integrated in time. Numerical examples for inner and outer free-surface flows are shown. The accuracy of the numerical solution is assessed either by checking mass and energy conservation or by comparing with reference solutions. Good results are generally obtained. Extended use of the developed algorithm to more applied problems in the context of naval hydrodynamics is now under development.


We consider a class of inviscid free surface flows where the free surface is of finite length and in which the pressure on the free boundary p b is different from the free stream pressure p ∞ . The aim of the paper is to determine the shape of the free surface as a function of the velocity ratio parameter λ . The free boundary problem is tackled by seeking a mapping z ═ f (ζ) such that the flow past a circle in the ζ-plane maps to a flow with constant pressure p b on the free surface in the z -plane. The formulation leads to an infinite system of coupled nonlinear equations for the coefficients in the mapping function. Remarkably, the system can be solved exactly to yield two families of free surface flows of the form z ═ ζ + λ 2 /ζ + a ( λ ) ln (ζ + b ( λ )/ζ ─ b ( λ )). The nature of the solutions, their limitations and possible extensions to them are discussed.


1991 ◽  
Vol 3 (12) ◽  
pp. 2995-3000 ◽  
Author(s):  
J.‐M. Vanden‐Broeck ◽  
Frédéric Dias

2018 ◽  
Vol 28 (3) ◽  
pp. 248-254 ◽  
Author(s):  
Georgios Fourtakas ◽  
Peter Stansby ◽  
Benedict Rogers ◽  
Steven Lind ◽  
Shiqiang Yan ◽  
...  

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