Documents disponibles écrits par cet auteur

Numerical study of saltation of non-uniform grains / Robert J. Bialik in Journal of hydraulic research, Vol. 49 N° 5 (Septembre/Octobre 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 5 (Septembre/Octobre 2011) . - pp. 697-701 Titre : Numerical study of saltation of non-uniform grains Type de document : texte imprimé Auteurs : Robert J. Bialik, Auteur Année de publication : 2011 Article en page(s) : pp. 697-701 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Collision  angle  Lagrangian  approach  Particle-bed  collision  Particle  diffusion  Saltation Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : A theoretical model of non-uniform saltating grains in a turbulent open-channel flow based on the Lagrangian approach is developed. In the analysis described herein, a more realistic stochastic model of particle-bed collision is proposed. Based on geometrical considerations, new formulas for the minimum and maximum values of the angle of the collision surface with an irregular bed are derived. A Monte Carlo simulation of the distribution of saltating and colliding particles is introduced. Numerical simulations of possible particles trajectories with different sizes in an open-channel flow are presented. It is demonstrated that the particle-bed collision mechanism exactly depends on different particles sizes and the bed structure. Application for the analysis of the longitudinal saltating particle diffusion is presented, and the problem with the initial conditions in numerical simulations of particle motion is briefly described. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.598025 [article] Numerical study of saltation of non-uniform grains [texte imprimé] / Robert J. Bialik, Auteur . - 2011 . - pp. 697-701. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 5 (Septembre/Octobre 2011) . - pp. 697-701 Mots-clés : Collision  angle  Lagrangian  approach  Particle-bed  collision  Particle  diffusion  Saltation Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : A theoretical model of non-uniform saltating grains in a turbulent open-channel flow based on the Lagrangian approach is developed. In the analysis described herein, a more realistic stochastic model of particle-bed collision is proposed. Based on geometrical considerations, new formulas for the minimum and maximum values of the angle of the collision surface with an irregular bed are derived. A Monte Carlo simulation of the distribution of saltating and colliding particles is introduced. Numerical simulations of possible particles trajectories with different sizes in an open-channel flow are presented. It is demonstrated that the particle-bed collision mechanism exactly depends on different particles sizes and the bed structure. Application for the analysis of the longitudinal saltating particle diffusion is presented, and the problem with the initial conditions in numerical simulations of particle motion is briefly described. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.598025

Particle-particle collision in Lagrangian modelling of saltating grains / Robert J. Bialik in Journal of hydraulic research, Vol. 49 N° 1 (Janvier/Fevrier 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 1 (Janvier/Fevrier 2011) . - pp. 23 - 31 Titre : Particle-particle collision in Lagrangian modelling of saltating grains Type de document : texte imprimé Auteurs : Robert J. Bialik, Auteur Année de publication : 2011 Article en page(s) : pp. 23 - 31 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Lagrangian  model  Particle-particle  collision  Saltating  particle  Sediment  transport  Turbulent  velocity  field Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : The effect of particle-particle collision on the trajectories of saltating grains in open-channel flows is investigated. The vertical distributions of saltating particles are also analysed. A stochastic particle-particle collision model was designed to determine the collision probability along a particle trajectory, based on the assumption that inter-particle collision frequency may be described by the formula of kinetic gas theory. This parameter is the key quantity for the calculation of collision probability. The Monte Carlo simulation method is used to obtain the velocity and concentration of saltating particles. It is the first attempt to apply a probabilistic inter-particle collision approach to Lagrangian modelling of saltating grains. Trajectories of different particles with and without particle-particle collision are compared with available data. The proposed procedure allows verification of the hypothesis regarding the effect of the particle-particle collision on sediment transport. The described mechanism affects the vertical particle concentration and therefore may play an essential role in bed-load sediment transport. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.informaworld.com/smpp/content~db=all~content=a933313380~frm=titlelink [article] Particle-particle collision in Lagrangian modelling of saltating grains [texte imprimé] / Robert J. Bialik, Auteur . - 2011 . - pp. 23 - 31. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 1 (Janvier/Fevrier 2011) . - pp. 23 - 31 Mots-clés : Lagrangian  model  Particle-particle  collision  Saltating  particle  Sediment  transport  Turbulent  velocity  field Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : The effect of particle-particle collision on the trajectories of saltating grains in open-channel flows is investigated. The vertical distributions of saltating particles are also analysed. A stochastic particle-particle collision model was designed to determine the collision probability along a particle trajectory, based on the assumption that inter-particle collision frequency may be described by the formula of kinetic gas theory. This parameter is the key quantity for the calculation of collision probability. The Monte Carlo simulation method is used to obtain the velocity and concentration of saltating particles. It is the first attempt to apply a probabilistic inter-particle collision approach to Lagrangian modelling of saltating grains. Trajectories of different particles with and without particle-particle collision are compared with available data. The proposed procedure allows verification of the hypothesis regarding the effect of the particle-particle collision on sediment transport. The described mechanism affects the vertical particle concentration and therefore may play an essential role in bed-load sediment transport. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.informaworld.com/smpp/content~db=all~content=a933313380~frm=titlelink