Mass transport in two-dimensional water waves

1991 ◽  
Vol 231 ◽  
pp. 395-415 ◽  
Author(s):  
Mohamed Iskandarani ◽  
Philip L.-F. Liu

Mass transport in various kind of two-dimensional water waves is studied. The characteristics of the governing equations for the mass transport depend on the ratio of viscous lengthscale to the amplitude of the free-surface displacement. When this ratio is small, the nonlinearity is important and the mass transport flow acquires a boundary-layer character. Numerical schemes are developed to investigate mass transport in a partially reflected wave and above a hump in the seabed. When the mass transport is periodic in the horizontal direction, a spectral scheme based on a Fourier–Chebyshev expansion, is presented for the solution of the equations. For the ease of a hump on the seabed, the flow domain is divided into three regions. Using the spectral scheme, the mass transport in the uniform-depth regions is calculated first. and the results are used to compute the steady flow in the inhomogeneous flow region which encloses the hump on the seabed.

1971 ◽  
Vol 49 (2) ◽  
pp. 385-389 ◽  
Author(s):  
T. Brooke Benjamin ◽  
J. J. Mahony

The discussion concerns free wave motions generated from rest in a finite region of an ocean of heavy liquid lying on a horizontal plane. It is shown that the horizontal fist moment of the free-surface displacement varies linearly with time. Hence, if the total volume displaced is not zero and therefore the centroid of the displacement is definable, the centroid travels with a constant horizontal velocity as the wave motion evolves. This conclusion holds exactly for waves of any amplitude and even remains applicable subsequent to the breaking of waves.


2020 ◽  
Vol 8 (6) ◽  
pp. 1941-1944

Numerical simulations have been carried out on a rectangular tank filled partially with liquid using volume of fluid technique. The tank has been given to and fro motion in one direction. Numerical simulation has been carried for a two dimensional case having laminar and unsteady flow. The changes in free surface displacement and dynamic pressure at different times has been observed using ANSYS software. The study was conducted for two sec. It was observed that free surface displacement of fluid increases with velocity. Also, with an increase in volume of liquid the sloshing effect decreases.


1972 ◽  
Vol 39 (1) ◽  
pp. 53-58 ◽  
Author(s):  
D. S. Weaver ◽  
T. E. Unny

This paper examines the influence of a parallel free surface on the hydroelastic stability of a flat panel. A quasi-two-dimensional approximation is made for the free surface displacement and the results compared with the more general but cumbersome three-dimensional solution. This comparison shows that the former approach is quite reasonable as well as being considerably simpler and more instructive. It is found that the free surface has no effect for depth ratios greater than about one half and is stabilizing for smaller depth ratios.


1974 ◽  
Vol 1 (14) ◽  
pp. 16
Author(s):  
Ole Gunnar Houmb

The two dimensional (directional) power spectrum gives an adequate description of water waves that may be regarded as a linear superposition of statistically independent waves. In such cases the sea surface is linear to the first order and the surface displacement is represented by CO n(t) = Z an sm(u> t + n) n=l where an are the amplitudes of individual waves and is a Tn randomly distributed phase angle, and the process is stationary. Under such circumstances the wave surface is Gaussian, which means that ordinates measured from MWL are normally distributed rf they are sampled at constant intervals of time. It is equally important that the wave heights are Rayleigh distributed. This formulation of the wave surface is widely used e.g. in wave forecasting. There are, however, phenomena such as wave breaking, energy transfer between wave components and surf beat which can only be described by higher order effects of wave motion (1, 2, 3, 4). In this case the two dimensional power spectrum fails to give an accurate description of the wave surface. This means that the first and second order moments (mean and covariance) no longer give all the probability information, and we have to consider higher order moments (5, 6, 7).


Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
J. Barry Greenberg ◽  
David Katoshevski

A theoretical investigation of the influence of a standing wave flow-field on the dynamics of a laminar two-dimensional spray diffusion flame is presented for the first time. The mathematical analysis permits mild slip between the droplets and their host surroundings. For the liquid phase, the use of a small Stokes number as the perturbation parameater enables a solution of the governing equations to be developed. Influence of the standing wave flow-field on droplet grouping is described by a specially constructed modification of the vaporization Damkohler number. Instantaneous flame front shapes are found via a solution for the usual Schwab–Zeldovitch parameter. Numerical results obtained from the analytical solution uncover the strong bearing that droplet grouping, induced by the standing wave flow-field, can have on flame height, shape, and type (over- or under-ventilated) and on the existence of multiple flame fronts.


2020 ◽  
Vol 10 (1) ◽  
pp. 534-547
Author(s):  
Jifeng Chu ◽  
Joachim Escher

Abstract When the vorticity is monotone with depth, we present a variational formulation for steady periodic water waves of the equatorial flow in the f-plane approximation, and show that the governing equations for this motion can be obtained by studying variations of a suitable energy functional 𝓗 in terms of the stream function and the thermocline. We also compute the second variation of the constrained energy functional, which is related to the linear stability of steady water waves.


Author(s):  
Didier Clamond

Steady two-dimensional surface capillary–gravity waves in irrotational motion are considered on constant depth. By exploiting the holomorphic properties in the physical plane and introducing some transformations of the boundary conditions at the free surface, new exact relations and equations for the free surface only are derived. In particular, a physical plane counterpart of the Babenko equation is obtained. This article is part of the theme issue ‘Nonlinear water waves’.


1998 ◽  
Vol 10 (9) ◽  
pp. 2405-2411 ◽  
Author(s):  
Z. C. Feng
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document