Aplicação do método do Kernel de densidade na modelagem lagrangiana da trajetória e evaporação de mancha de óleo em águas rasas

• Autor(a) principal: Gaze, Felipe Nascimento
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/10220
• topic: Kernel; Lagrangian model; Oil spill modeling; Evaporation; Modelagem computacional lagrangiana; Engenharia Sanitária; Modelagem de dados; Derramamento de óleo; Lagrange, Funções de; Kernel, Funções de; Evaporação; 628

Targeting the development of a Lagrangian Particle Dispersion Model (LPDM) that simulates the movement and fate of oil slick in the marine environment, the work concentrates its efforts in the implementation of computer algorithms to achieve the proposed objective. The first algorithm is related to the kernel density method for calculating the concentration of a pollutant, implemented as an alternative to the box method. Six forms for the kernel function are inserted in the LPDM: Gaussian, Epanechnikov, bi-, tri-, quad-and quintweight. In a test conducted in a square bay (mm000.5000.5×) and forced by a tidal wave, and comparing the results with an analytical solution, all forms of kernel achieve accurate concentration compared to the method box for any number of particles released .Among the forms of the kernel, the Gaussian is shown slightly more advantageous than the others. An algorithm that simulates the process of evaporation of the oil slick in the marine environment is also implemented in order to represent at least one of the physical-chemical processes active in the oil slick at sea. Based on the method of exposure evaporated, the LPDM simulates satisfactorily the loss of mass due to evaporation when the data are compared with results from field, showing a tendency to eliminate more than % 50 the volume of a light oil already in the firsth24 , with a loss of mass equal to almost zero after h40 . A simulation of a hypothetical oil spill in the Espírito Santo bay within the Porto de Tubarão, is conducted to illustrate an application of the model developed. The procedure finds a provision of the slick to leave the region through the southeast exit, and the other fraction of the oil still trapped in the port. In the case of a heavy oil, the rate of evaporation is around %30 of the loss of volume in the first day after the spill.