scholarly journals Computational analysis of water entry of a circular section at constant velocity based on Reynold’s averaged Navier-Stokes method

2017 ◽  
Author(s):  
M. Maruf Uddin ◽  
Muzaddid-E-Zaman Fuad ◽  
Md. Mashiur Rahaman ◽  
M. Rabiul Islam
Keyword(s):  
Constant Velocity ◽  
Computational Analysis ◽  
Water Entry ◽  
Navier Stokes ◽  
Circular Section

Computational analysis of asymmetric water entry of wedge and ship section at constant velocity

2016 ◽  
Author(s):  
Md. Mashiur Rahaman ◽  
Al Habib Ullah ◽  
Laboni Afroz ◽  
Sharmin Shabnam ◽  
M. A. Rashid Sarkar
Keyword(s):  
Constant Velocity ◽  
Computational Analysis ◽  
Water Entry ◽  
Asymmetric Water Entry

scholarly journals Computational analysis of two-dimensional wing aeroelastic flutter using Navier-Stokes model

2018 ◽  
Vol 9 (4) ◽  
pp. 3459-3472 ◽  
Author(s):  
Magdy Saeed Hussin ◽  
Ashraf Ghorab ◽  
Mohamed A. El-Samanoudy
Keyword(s):  
Computational Analysis ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Aeroelastic Flutter

scholarly journals Numerical Investigation on the Water Entry of Several Different Bow-Flared Sections

2020 ◽  
Vol 10 (22) ◽  
pp. 7952
Author(s):  
Qiang Wang ◽  
Boran Zhang ◽  
Pengyao Yu ◽  
Guangzhao Li ◽  
Zhijiang Yuan
Keyword(s):  
Stokes Equations ◽  
Water Entry ◽  
Navier Stokes ◽  
Hydrodynamic Characteristics ◽  
Time Step ◽  
Navier Stokes Equations ◽  
Surface Evolution ◽  
Mesh Method ◽  
The Difference ◽  
Dynamics Method

The bow-flared section may be simplified in the prediction of slamming loads and whipping responses of ships. However, the difference of hydrodynamic characteristics between the water entry of the simplified sections and that of the original section has not been well documented. In this study, the water entry of several different bow-flared sections was numerically investigated using the computational fluid dynamics method based on Reynolds-averaged Navier–Stokes equations. The motion of the grid around the section was realized using the overset mesh method. Reasonable grid size and time step were determined through convergence studies. The application of the numerical method in the water entry of bow-flared sections was validated by comparing the present predictions with previous numerical and experimental results. Through a comparative study on the water entry of one original section and three simplified sections, the influences of simplification of the bow-flared section on hydrodynamic characteristics, free surface evolution, pressure field, and impact force were investigated and are discussed here.

scholarly journals Lr-LpStability of the Incompressible Flows with Nonzero Far-Field Velocity

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Jaiok Roh
Keyword(s):  
Constant Velocity ◽  
Incompressible Flows ◽  
Temporal Stability ◽  
Stationary Solutions ◽  
Decay Rates ◽  
Navier Stokes ◽  
Far Field ◽  
Spatial Direction ◽  
Field Velocity ◽  
The Stability

We consider the stability of stationary solutionswfor the exterior Navier-Stokes flows with a nonzero constant velocityu∞at infinity. Foru∞=0with nonzero stationary solutionw, Chen (1993), Kozono and Ogawa (1994), and Borchers and Miyakawa (1995) have studied the temporal stability inLpspaces for1<pand obtained good stability decay rates. For the spatial direction, we recently obtained some results. Foru∞≠0, Heywood (1970, 1972) and Masuda (1975) have studied the temporal stability inL2space. Shibata (1999) and Enomoto and Shibata (2005) have studied the temporal stability inLpspaces forp≥3. Then, Bae and Roh recently improved Enomoto and Shibata's results in some sense. In this paper, we improve Bae and Roh's result in the spacesLpforp>1and obtainLr-Lpstability as Kozono and Ogawa and Borchers and Miyakawa obtained foru∞=0.

Modélisation tridimensionnelle de l'écoulement au voisinage d'un aménagement portuaire

1989 ◽  
Vol 16 (6) ◽  
pp. 829-844
Author(s):  
A. Soulaïmani ◽  
Y. Ouellet ◽  
G. Dhatt ◽  
R. Blanchet
Keyword(s):  
Free Surface ◽  
Computational Analysis ◽  
Stokes Equations ◽  
A Priori ◽  
Three Dimensional ◽  
Free Surface Flows ◽  
Solution Algorithm ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Surface Flows

This paper is devoted to the computational analysis of three-dimensional free surface flows. The model solves the Navier-Stokes equations without any a priori restriction on the pressure distribution. The variational formulation along with the solution algorithm are presented. Finally, the model is used to study the hydrodynamic regime in the vicinity of a projected harbor installation. Key words: free surface flows, three-dimensional flows, finite element method.

Simulation on the Process of Cavity Wall Expansion of Cone at Constant Speed Water-Entry

2013 ◽  
Vol 419 ◽  
pp. 97-102
Author(s):  
Wei Cao ◽  
Chun Tao He ◽  
Cong Wang
Keyword(s):  
Computational Simulation ◽  
Water Entry ◽  
Constant Speed ◽  
Cavity Wall ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Half Angle ◽  
Expansion Dynamic ◽  
Different Depths ◽  
Volume Method

Computational simulation investigation which is based on the Navier-Stokes equation, finite-volume method, dynamic mesh method, and volume of fluid method, was carried out principally on the constant speed vertical water entry of the cone with 75 degree and a half angle. Based on this, the cavity generation and the process of cavity wall expansion of the cone with 75 degree and a half angle were analyzed. Through analyzing the expansion dynamic for the cavity wall in different depths, the velocity and acceleration with time in the process of cavity wall expansion were obtained, and the disturbances and splash feature laws of the free surface near the entrance of the cavity after cones water-entry were analyzed too.

Numerical Solution of 3-D Water Entry Problems With a Constrained Interpolation Profile Method

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Qingyong Yang ◽  
Wei Qiu
Keyword(s):  
Numerical Solutions ◽  
Stokes Equations ◽  
Type Equation ◽  
Water Entry ◽  
Navier Stokes ◽  
Time Step ◽  
Constrained Interpolation ◽  
Navier Stokes Equations ◽  
Highly Nonlinear ◽  
Calm Water

This paper presents the numerical solutions of slamming problems for 3D bodies entering calm water with vertical and oblique velocities. The highly nonlinear water entry problems are governed by the Navier-Stokes equations and were solved by a constrained interpolation profile (CIP)-based finite difference method on a fixed Cartesian grid. In the computation, the 3D CIP method was employed for the advection calculations and a pressure-based algorithm was applied for the nonadvection calculations. The solid body and the free surface interfaces were captured by density functions. For the pressure computation, a Poisson-type equation was solved at each time step by using the conjugate gradient iterative method. Validation studies were carried out for a 3D wedge, a cusped body vertically entering calm water, and the oblique entry of a sphere into calm water. The predicted hydrodynamic forces on the wedge, the cusped body, and the sphere were compared with experimental data.

Navier–Stokes solver for water entry bodies with moving Chimera grid method in 6DOF motions

2016 ◽  
Vol 140 ◽  
pp. 19-38 ◽  
Author(s):  
Van-Tu Nguyen ◽  
Duc-Thanh Vu ◽  
Warn-Gyu Park ◽  
Chul-Min Jung
Keyword(s):  
Grid Method ◽  
Water Entry ◽  
Navier Stokes ◽  
Chimera Grid

scholarly journals Brownian Oscillators Driven by Correlated Noise in a Moving Trap

2012 ◽  
Vol 63 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Lukáš Glod ◽  
Gabriela Vasziová ◽  
Jana Tóthová ◽  
Vladimír Lisý
Keyword(s):  
Langevin Equation ◽  
Analytical Solutions ◽  
Constant Velocity ◽  
Navier Stokes ◽  
Generalized Langevin Equation ◽  
Correlated Noise ◽  
Inertial Term ◽  
Coloured Noise ◽  
Exact Analytical Solutions ◽  
Brownian Oscillator

Brownian Oscillators Driven by Correlated Noise in a Moving TrapBrownian oscillator, ie a micron-sized or smaller particle trapped in a thermally fluctuating environment is studied. The confining harmonic potential can move with a constant velocity. As distinct from the standard Langevin theory, the chaotic force driving the particle is correlated in time. The dynamics of the particle is described by the generalized Langevin equation with the inertial term, a coloured noise force, and a memory integral. We consider two kinds of the memory in the system. The first one corresponds to the exponentially correlated noise and in the second case the memory naturally arises within the Navier-Stokes hydrodynamics. Exact analytical solutions are obtained in both the cases using a simple and effective method not applied so far in this kind of problems.

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