scholarly journals Properties of the pressure field in highly nonlinear free surface flows with critical jet

2021 ◽  
Vol 128 (1) ◽  
Author(s):  
Yves-Marie Scolan ◽  
Stéphane Etienne
Keyword(s):  
Free Surface ◽  
Pressure Field ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Highly Nonlinear ◽  
Nonlinear Free Surface

A B-Spline Based BEM for Unsteady Free-Surface Flows

1999 ◽  
Vol 43 (01) ◽  
pp. 13-24
Author(s):  
M. Landrini ◽  
G. Grytøyr ◽  
O. M. Faltinsen
Keyword(s):  
Free Surface ◽  
Evolution Equations ◽  
Boundary Integral Equations ◽  
Fluid Dynamic ◽  
Domain Boundary ◽  
Free Surface Flows ◽  
Boundary Integral ◽  
Surface Flows ◽  
B Spline ◽  
Nonlinear Free Surface

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.

Exact solutions for a class of nonlinear free surface flows

1991 ◽  
Vol 434 (1892) ◽  
pp. 677-682 ◽  
Keyword(s):  
Free Surface ◽  
Free Boundary ◽  
Infinite System ◽  
Free Stream ◽  
Constant Pressure ◽  
Velocity Ratio ◽  
Mapping Function ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Nonlinear Free Surface

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.

Numerical Simulations of Highly Nonlinear Steady and Unsteady Free Surface Flows

2011 ◽  
Vol 23 (6) ◽  
pp. 683-696 ◽  
Author(s):  
Chi Yang ◽  
Fuxin Huang ◽  
Lijue Wang ◽  
De-cheng Wan
Keyword(s):  
Free Surface ◽  
Numerical Simulations ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Highly Nonlinear

Nonlinear free‐surface flows past a submerged inclined flat plate

1991 ◽  
Vol 3 (12) ◽  
pp. 2995-3000 ◽  
Author(s):  
J.‐M. Vanden‐Broeck ◽  
Frédéric Dias
Keyword(s):  
Free Surface ◽  
Flat Plate ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Nonlinear Free Surface

Computational Techniques for Stabilized Edge-Based Finite Element Simulation of Free-Surface Flows

2008 ◽  
Author(s):  
Renato N. Elias ◽  
Milton A. Gonc¸alves ◽  
Alvaro L. G. A. Coutinho ◽  
Paulo T. T. Esperanc¸a ◽  
Marcos A. D. Martins ◽  
...  
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Free Surface Flows ◽  
Computational Techniques ◽  
Element Formulation ◽  
Normal Velocity ◽  
Parallel Edge ◽  
Surface Flows ◽  
Highly Nonlinear ◽  
Edge Based

Free-surface flows occur in several problems in hydrodynamics, such as fuel or water sloshing in tanks, waves breaking in ships, offshore platforms, harbors and coastal areas. The computation of such highly nonlinear flows is challenging since free-surfaces commonly present merging, fragmentation and breaking parts, leading to the use of interface capturing Eulerian approaches. In such methods the surface between two fluids is captured by the use of a marking function which is transported in a flow field. In this work we discuss computational techniques for efficient implementation of 3D incompressible SUPG/PSPG finite element methods to cope with free-surface problems with the Volume-of-Fluid (VOF) method [1]. The pure advection equation for the scalar marking function was solved by a fully implicit parallel edge-based SUPG finite element formulation. Global mass conservation is enforced adding or removing mass proportionally to the absolute value of the normal velocity of the interface. We introduce parallel edge-based data structures, a parallel dynamic deactivation algorithm to solve the marking function equation only in a small region around the interface. The implementation is targeted to distributed memory systems with cache-based processors. The performance and accuracy of the proposed solution method is tested in the simulation of the water impact on a square cylinder and in the propagation of a solitary wave.

On the Coupling of Incompressible SPH with a Finite Element Potential Flow Solver for Nonlinear Free-Surface Flows

2018 ◽  
Vol 28 (3) ◽  
pp. 248-254 ◽  
Author(s):  
Georgios Fourtakas ◽  
Peter Stansby ◽  
Benedict Rogers ◽  
Steven Lind ◽  
Shiqiang Yan ◽  
...  
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Potential Flow ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Flow Solver ◽  
Incompressible Sph ◽  
Nonlinear Free Surface

Multi-Resolution MPS Method for Free Surface Flows

2016 ◽  
Vol 13 (04) ◽  
pp. 1641018 ◽  
Author(s):  
Zhenyuan Tang ◽  
Youlin Zhang ◽  
Decheng Wan
Keyword(s):  
Free Surface ◽  
Pressure Field ◽  
Fine Particles ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Mps Method ◽  
Time Simulation ◽  
Long Time ◽  
Moving Particle ◽  
Dam Breaking

A multi-resolution moving particle semi-implicit (MPS) method is applied into two-dimensional (2D) free surface flows based on our in-house particle solver MLParticle-SJTU in the present work. Considering the effect of different size particles, both the influence radiuses of two adjacent particles are replaced by the arithmetic mean of their interaction radiuses. Then the modifications for kernel function of differential operator models are derived, respectively. In order to validate the present multi-resolution MPS method, two cases are carried out. Firstly, a hydrostatic case is performed. The results show that the contour of pressure field by multi-resolution MPS is quite in agreement with that by single resolution MPS. Especially, the multi-resolution MPS can still provide a relative smooth pressure together with the single resolution MPS in the vicinity of the interface between the high resolution and low resolution particles. For a long time simulation, the kinetic energy of particles by multi-resolution MPS can decrease quickly to the same level as that of single resolution MPS. In addition, a 2D dam breaking flow is simulated and the multi-resolution case can run stably during the whole simulation. The pressure by the multi-resolution MPS is in agreement with experimental data together with single resolution MPS. The contour of pressure field by the former is also similar to that by the later. Finally, the simulation by multi-resolution MPS is as accurate as the traditional MPS with fine particles distributed in the whole domain and the corresponding CPU time can be reduced.

Sign in / Sign up

Export Citation Format

Share Document