MOVIMENTO DE PARTÍCULAS DE SEDIMENTOS EM ESCOAMENTOS COM SUPERFÍCIE LIVRE PELA TEORIA DOS PROCESSOS ALEATÓRIOS

Código

PAP054

Autores

GERALDO WILSON JUNIOR, Cid da Silva Garcia Monteiro

Tema

MEDIÇÃO, MODELAGEM, TÉCNICAS E TECNOLOGIAS NO CONTEXTO DA HIDROSSEDIMENTOLOGIA

Resumo

The two-dimensional movements: of fine suspended sediments (pelitic and non-pelitic), and of pollutants (fixed in fine sediments, dissolved or in colloidal forms), as well as the bed loadmovements of non-pelitic sediments, characterize random processes whose elementary events are the trajectories of the individual particles. The two-dimensional trajectory ?(x,z,t)results from the combination of two chronological series of displacements in the directions i=1,3; intercalatedby periods in which the particle ceases to advance in these directions. These two independent 1-Dseries are considered in this paper.When they are described by Homogeneous Poissonian Random Processes, the resulting 2-Dmodel is also Homogeneous Poissonian, defined by four mobility density functions that characterize the motions of the particles, in time and in the directions xandz: ?x1(t,n), ?z1(t,n), ?t2(x,n) and?t2(z,n), where nrepresents the number of displacements in the intervals [0,t]; [0,x] and[0,z],respectively. The objectives of this work are: (i) to emphasize the importance of the random 2-D models, longitudinal and vertical, for the analysis of the bed load and in suspensionmovements; (ii) present the experimental equipment and devices that allow the study of the movementsof non-cohesive and cohesive sediments with vertical transfers: decantation, deposition and erosion of the bed; and (iii) use the results obtained for calibration and validation of the theoretical models.In order to apply the 1-DPoissonianmodels, the PAICON(Random Processes with Instantaneous and Continuous Injections) wereconsidered (Monteiro and Wilson-Jr., 2001), which was expanded to includethe two-dimensional case: PAICON-2D.It is concluded that the 2-DHomogeneous Poissonian Random Processes accurately describe sediment and pollutant suspension motions for any instantaneous and continuous immersion type.For bed load movements, due to the bed mobile forms, more complex models are needed: Poissonian Non-Homogeneous and Non-Poissonian models (Wilson-Jr., 1987).Topics of the analyticaldevelopment of these 1-Dand 2-Dmodels werepresented in Vukmirovi? (1975), Todorovi? et al. (1976), Wilson-Jr. (1987), Monteiro (2004), Wilson-Jr. and Monteiro (2016, 2017, 2018), among other publicationsof the authors