Restauração de imagens digitais com texturas utilizando técnicas de decomposição e equações diferenciais parciais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leis de Conservação Hiperbólicas 2D com Termo Fonte Stiff

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Zeros de Polinômios Perturbados

Pós-graduação em Matematica Aplicada e Computacional - FCT

Estabilidade global e bifurcação de Hopf em um modelo de HIV baseado em sistemas do tipo Lotka-Volterra

Pós-graduação em Matematica Aplicada e Computacional - FCT

Estudo da estabilidade do método das linhas usando a dinâmica de um cabo flexível

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aplicação da computação simbólica na resolução de problemas de condução de calor em cilindros vazados com condições de contorno convectivas

Pós-graduação em Engenharia Mecânica - FEG

A Numerical Study of the FENE-CR Model Applied to a Jet Flow Problem

The FENE-CR model is investigated through a numerical algorithm to simulate the time-dependent moving free surface flow produced by a jet impinging on a flat surface. The objective is to demonstrate that by increasing the extensibility parameter L, the numerical solutions converge to the solutions obtained with the Oldroyd-B model. The governing equations are solved by an established free surface flow solver based on the finite difference and marker-and-cell methods. Numerical predictions of the extensional viscosity obtained with several values of the parameter L are presented. The results show that if the extensibility parameter L is sufficiently large then the extensional viscosities obtained with the FENE-CR model approximate the corresponding Oldroyd-B viscosity. Moreover, the flow from a jet impinging on a flat surface is simulated with various values of the extensibility parameter L and the fluid flow visualizations display convergence to the Oldroyd-B jet flow results.

Técnica para dedução do modelo algébrico PTT, aplicações e análises numéricas em escoamentos bidimensionais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento caótico em modelos matemáticos de câncer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sólitons e Oscillons em cenários com violações da simetria de Lorentz

Pós-graduação em Física - FEG

Caracterização e redução das oscilações espúrias resultantes da representação de linhas de transmissão por meio de elementos discretos de circuitos

Pós-graduação em Engenharia Elétrica - FEIS

Soluções numéricas de Equações Diferenciais Fracionária e Ordinária para o cálculo da distribuição da concentração em um sistema de compartimento

The purpose of this work was the study of numerical methods for differential equations of fractional order and ordinary. These methods were applied to the problem of calculating the distribution of the concentration of a given substance over time in a given physical system. The two compartment model was used for representation of this system. Comparison between numerical solutions obtained were performed and, in particular, also compared with the analytical solution of this problem. Finally, estimates for the error between the solutions were calculated

Spatial dynamics of a population with stage-dependent diffusion

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Existence and multiplicity of solutions for a prescribed mean-curvature problem with critical growth

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reducing the spurious oscillations in the lumped parameters model using low-pass filter

Voltages and currents in the transmission line are described by differential equations that are difficult to solve due soil and skin effect that has to be considered for accurate results, but it increases their complexity. Therefore there are some models to study the voltages and currents along in transmission line. The distributed parameters model that transforms the equations in time domain to the frequency domain and once the solutions are obtained, they are converted to time domain using the Inverse Laplace Transform using numerical methods. Another model is named lumped parameters model and it considers the transmission line represented by a pi-circuit cascade and the currents and voltages are described by state equations. In the simulations using the lumped parameters model, it can be observed the presence of spurious oscillations that are independent of the quantity of pi-circuits used and do not represent the real value of the transient. In this work will be projected a passive low-pass filter directly inserted in the lumped parameters model to reduce the spurious oscillations in the simulations, making this model more accurate and reliable for studying the electromagnetic transients in power systems.