Modelo de escoamento multifásico para estudo da interação onda/sedimento
Nenhuma Miniatura disponível
Data
2014-04-29
Autores
Piccoli, Fábio Pavan
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal do Espírito Santo
Resumo
Multiphase flow models are widely used in many fields of environmental research, such as fluidized beds, gas dispersion in liquids, dam breaks, oil spill and others physical and chemical processes that use more than one property. Thus, a multiphase model to study the dynamics of two distinct properties represented on reference Eulerian-Lagrangian was developed. In order to study the dynamics of sediment transport due to wave’s action, a non-linear wave Boussinesq model in Eulerianframe, in which the numerical formulation based on Wei et al. (1995), and a Lagrangian particle model, whose formulation is given by the Newtonian principle of motion, has beendeveloped. In the Lagrangian particle model was added the scheme of hard-spheres particle collision. The coupling between the two models has been doing withthe wave transferring momentum to sedimentparticles, which is carried by the flow. For the wave’s model, the wave maker, defined by a Gaussian function, piston-paddle and flap-paddle, and the effects due to the depth of the waves were tested. The Gaussian wave maker showed better consistency in the generation of waves, getting errors about 0.11% compared tothe linear theory forkh . The wave’s nonlinearity simulated by the 2 nd order dispersion Boussinesq-wave model showed satisfactory results when compared withexperiment of wave propagation over a trapezoidal obstacle, where the deformation of the wave on the underwater structure is in agreement with literature data. In addition to the granular model was also tested in two experiments: the first, which simulates a dam break in a tank containing water-air; and the second experiment, the dam break interact withan obstacle in the center of the tank. In both experiments, the collision model was effective in the treatment of the interaction between the particles and the wall, and allowed the evidence of physical processes that are complicated to be simulated bymodels that use regular grids. For the coupling of wavesediment model, the algorithm has been tested with data obtained from the literature as the morphology of the bed. The results were compared with analytical data and numerical models, and it showed a certain agreement on points of erosion, sedimentation and change in shape of the sand bar.
Descrição
Palavras-chave
Multiphase flow , Boussinesq equations , Collision , Particles , Gravitational wave , Sediments transport , Escoamento multifásico , Colisões (Física) , Ondas de rádio - Propagação , Equações de Boussinesq , Colisão (Física) , Partículas (Física, química, etc.) , Ondas gravitacionais , Transporte de sedimentos
Citação
PICCOLI, Fábio Pavan. Modelo de escoamento multifásico para estudo da interação onda/sedimento. 2014. 177 f. Dissertação (Mestrado em Engenharia Ambiental) - Universidade Federal do Espírito Santo, Centro Tecnológico, Vitória, 2014.