n° 1396 Conférence d'ouverture : The rogue waves in the ocean - review

Efim Pelinovsky Christian Kharif Alexey Slunyaev
Institute of Applied Physics
Our talk focuses on extreme wave events called rogue waves. They are among the waves naturally observed by people on the sea surface that represent inseparable feature of the Ocean. Rogue waves appear suddenly from nowhere, cause danger and disappear at once. They may occur at the surface of a relatively calm sea, reach not very high amplitudes, but be fatal for ships and crew due do their unexpectedness and abnormal features. The collection of observed rogue waves is presented. The physical mechanisms of the rogue wave formation are reviewed.
communication programmée pour mercredi matin 9H30 salle M

n° 1395 Strong amplification of water waves on non-reflected beaches

Ira Didenkulova Efim Pelinovsky
Institute of Applied Physics
Water wave amplification on beaches of a small slope is significant because there is no reflection. Here we demonstrate the same character of significant wave amplification even the depth is an arbitrary (not smoothed) function of offshore coordinate. Two examples of special bottom profiles when wave equation has a rigorous solution in the form of a traveling wave are found. The reflection and transmission of the wave approaching the non-reflecting beach are studied.
communication programmée pour mercredi matin 10H10 salle M

n° 1394 Short term dynamics of a free falling jet due to solitonic collision

Julien Touboul Julien Chambarel Christian Kharif
LSEET
The impact of two steep solitonic waves propagating in counter directions leads to the formation of a free fall residual jet. We investigate numerically and theoretically the characteristics of this jet, including the criteria of formation, and the short term dynamics. The numerical approach is based on a boundary integral elements method, allowing to compute the pressure of the inner flow. A theoretical description based on potential flow theory is introduced to describe the short term evolution of the jet.
communication programmée pour mercredi matin 10H50 salle M

n° 1393 Modutional instability in the presence of forcing and dissipation

Christian Kharif Roberto Kraenkel Miguel Manna Roland Thomas
Institut de Recherche sur les Phénomenes Hors Equilibre
The modulational instability of gravity wavetrains on the surface of water in the presence of wind and dissipation is considered. The wind regime is that of validity of Miles' theory and the viscosity is small. A perturbed nonlinear SchrÄodinger equation describing the evolution of a narrow-banded wavepacket is derived. It is found in the presence of wind forcing and dissipation that trains of long gravity waves are less unstable to modulational perturbations than trains of short gravity waves.
communication programmée pour mercredi matin 11H10 salle M

n° 1400 Comparative analysis of classical models (MARS3D, AZOV3D) and lattice Boltzmann models for shallow water hydrodynamics computations

Alexander Sukhinov Elena Alexeenko Boris Sidorenko Alexander Chistyakov Franck Dumas
Taganrog Institute of Technology
Different numerical approaches of hydrodynamics of shallow water basins are considered and compared. Two approaches are developped in TIT-Russia: one of them is classical and based on numerical solution of the Navier-Stokes equations by Pressure-Correction method, another (developed several years ago) is based on the solution of the Lattice Boltzmann kinetic equation. The comparative analysis of these two approaches with MARS3D is performed for a shallow water basin example: «Etang de Berre».
communication programmée pour mercredi matin 11H30 salle M

n° 1401 Turbulent mixing and stable current structures for Etang de Berre

Elena Alexeenko Alexander Sukhinov Alexander Chistyakov Bernard Roux Dominique Fougère
Taganrog Institute of Technology
Parameterization of coefficient of vertical turbulent exchange plays important role in the hydrodynamics of shallow water basin. Relevant parameters are determined on the basis of ADCP in situ experiments. They are implemented in Azov3D package developed at TIT-Russia. They are used to determine the currents in shallow water basins: Etang de Berre, Etang de Bolmon and Azov Sea. Comparison are performed with currents computed using another well known package (MARS3D).
communication programmée pour mercredi matin 11H50 salle M

n° 1397 Modelling of the enar-field distribution of pollutants from a coastal outfall subject to tidal currents

Tatyana Lyubimova Natalya Shumilova Shengping Luo Bernard Roux
Institute of Continuous Media Mechanics UB RAS
Pollutant distribution from a coastal outfall is studied accounting for tidal currents. The problem is solved using k-eps model. The constants in the logarithmic law for vertical velocity profile in the bbl (bottom boundary layer) are obtained by processing experimental data from a current profiler. The near-field distribution of pollutant concentration at different distances from the diffusor are obtained for different times, in terms of ambient flow velocity and outfall discharge characteristics.
communication programmée pour mercredi après midi 13H40 salle M

n° 1402 Three dimensional modeling of large water reservoirs with complex geometry and essential density inhomogeneity in depth

Tatyana Lyubimova Anatoly Lepikhin N.S. Shumilova
Institute of Continuous Media Mechanics UB RAS
The paper is devoted to the development of hydrodynamic model of the largest water intake of Perm Region, located in the merging zone of two rivers with significantly different hydrochemical regimes, in the direct stock dams of Kama Hydroelectric Station. A combination of 2D and 3D calculation schemes is implemented. Numerical results will be applied for the optimization of technical characteristics and modes of operation of water intake and Kama Hydroelectric Station in order to improve the quality of water.
communication programmée pour mercredi après midi 14H00 salle M

n° 1399 Numerical modeling of a dilution and transport of highly salty effluent in water bodies

Anatoly Lepikhin Tatyana Lyubimova Ya.N. Parshakova Alexey Tiunov
Mining Institute UB RAS
The paper focuses on modeling of dilution and transport of highly salty effluent in water bodies. The modeling is made for three-dimensional unsteady regimes of turbulent mixing in the conditions of strong density stratification. Numerical results allow to determine the limits of applicability of two-dimensional hydrodynamic models and to estimate the maximal possible environmentally safe volumes of highly salty effluent disposal.
communication programmée pour mercredi après midi 14H20 salle M

n° 1386 Physical phenomena governing the behaviour of wildfires : numerical simulation of crown fires in boreal fores

Dominique Morvan Konstantin Gavrilov Dmitry Lyubimov
Laboratoire M2P2
This paper presents the physical phenomena contributing to the behaviour of wildfires. The problem was formulated using a multiphase approach, including the set of balance equations governing the coupled system formed by the vegetation and the surrounding atmosphere in the vicinity of the fire front. Some numerical simulations carried out for a crown fire in boreal forest are compared to data collected during an experimental campaign conducted in the North West territories in Canada.
communication programmée pour mercredi après midi 15H40 salle M

n° 1387 Assessment of the plume theory predictions of crown scorch using transport models

Jean-Luc Dupuy Vladimir Konovalov François Pimont Dominique Morvan Rod Linn
INRA
The aim of our work is to study numerically crown scorch as the effects of a fire line spreading through surface fuel under a tree canopy. The objective was to assess the usual assumptions made when one uses the Van Wagner criteria, which are indeed simple predictive models for crown scorch height, to estimate crown scorch. For this purpose the FIRESTAR 2D and FIRETEC wildfire simulators are used. We simulated the fire line by a heat source at ground level and mainly investigated the temperature field. As a first step, we ran computations of thermal plumes with no-wind and with no canopy, for first comparison to plume theory. The influence of crown existence on the temperature field above the heat source, as well as on crown scorch, was then investigated. As a second step, the effect of a wind to the plume, as well as to crown scorch, was shown for the no-canopy and canopy cases.
communication programmée pour mercredi après midi 16H00 salle M

n° 1398 Simulation of quasi-static and dynamic deformation processes in the zones of volcanic activity

Valeriy Pavlovich Matveenko Varvara Bogoyavlenskaya N.A. Trufanov I.N. Shardakov
Institute of Continuous Media Mechanics, UB RAS
The paper investigates the quasi-static and dynamic deformation processes in the zones of volcanic activity using for this purpose the methods of mathematical simulation. The mathematical formulation of the problem is based on the principle of virtual displacements, and numerical realization of the variational equation is based on the finite-element method. The possibilities of pressure recording in the magma chamber by means of measuring deformations at the outer Earth’s crust have been found. The vibrogram relationships have been obtained to identify the points of possible sensor location.
communication programmée pour mercredi après midi 16H20 salle M