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Papers by Marcos Lourenço
Procceedings of the 19th Brazilian Congress of Thermal Sciences and Engineering, 2022
American journal of heat and mass transfer, 2016
This paper presents a numerical study of fluid flow and natural convection inside cubical cavitie... more This paper presents a numerical study of fluid flow and natural convection inside cubical cavities using the finite volume method with second order schemes. Cubical cavities of various sizes with three different thermal configurations were considered, where two opposite vertical walls are isothermal and the other walls are either adiabatic or conducting (with linear temperature variation). The numerical simulations were performed for air and gases with Prandtl number 0.71 under the influence of variable Rayleigh numbers covering the range 10 3-10 7. The effects of the three thermal configurations in terms of velocities and temperatures were investigated for both steady and unsteady flow regimes. Additionally, the magnitudes of local and average Nusselt numbers in each direction of the cubical cavity were scrutinized. Using conducting walls, the heat transfer analysis in different directions divulged that the heat flow through the top/bottom walls surpasses 1/3 of the total heat flow of the cubical cavity. Overall, the collection of numerical results demonstrates good agreement when compared with experimental-based and numerical-based publications.
Procceedings of the 19th Brazilian Congress of Thermal Sciences and Engineering
XXVI Seminário de Iniciação Científica e Tecnológica da UTFPR, Oct 15, 2021
O objetivo deste trabalho e analisar a influencia do indice de Power Law na queda de pressao loca... more O objetivo deste trabalho e analisar a influencia do indice de Power Law na queda de pressao localizada de um escoamento em uma geometria de contracao abrupta. Para essa finalidade foi utilizado o software livre OpenFOAM, o escoamento foi modelado matematicamente com as equacoes de conservacao de massa, quantidade de movimento e o modelo de viscosidade de Power Law. O modelo numerico foi resolvido utilizando o metodo dos volumes finitos. Foram realizadas duas simulacoes variando o indice de Power Law. Foi concluido que na secao de contracao a queda de pressao do fluido com indice de Power Law maior e menos significativa e na regiao a jusante da contracao a queda de pressao do fluido com indice de Power Law maior e mais significativa.
No presente trabalho e simulado um problema de escoamento de fluido em uma contracao abrupta, que... more No presente trabalho e simulado um problema de escoamento de fluido em uma contracao abrupta, que e muito comum na geometria de brocas de perfuracao de pocos de petroleo. O fluido simulado e newtoniano e incompressivel e foi feita a simulacao de duas geometrias diferentes, um quarto de um tubo e uma fatia dessa geometria. E utilizada a metodologia dos volumes finitos para resolver as equacoes diferenciais na forma de equacoes algebricas. O software utilizado para a realizacao do trabalho foi o OpenFOAM , que e vantajoso por ser um software livre e codigo aberto. Por fim, sao apresentados resultados atraves de imagem em escala de cores e tambem da comparacao das curvas de velocidade para as duas malhas, e e avaliado a viabilidade da ferramenta Wedge do software OpenFOAM .
Neste trabalho, sao feitas analises dos dados de um modulo Peltier, construido com dissipador de ... more Neste trabalho, sao feitas analises dos dados de um modulo Peltier, construido com dissipador de calor, em uma caixa de poliestireno de 11x19x14 cm. Uma estimativa para o COP e a perda de calor no dispositivo de resfriamento termoeletrico tambem sao apresentados para diferentes configuracoes. As temperaturas foram medidas por sensores digitais que se apresentam em diferentes configuracoes por meio de uma fonte de alimentacao variavel.
Journal of the Brazilian Society of Mechanical Sciences and Engineering
The Canadian Journal of Chemical Engineering
Boundary Elements and other Mesh Reduction Methods XLII
A simplified fluid-structure interaction model, consisting of a cylinder tethered by a spring sys... more A simplified fluid-structure interaction model, consisting of a cylinder tethered by a spring system interacting dynamically with an incompressible two-dimensional lid-driven cavity flow, is solved using the immersed boundary method. Results show that when the spring forces are weaker than the fluid drag force, the springs stretch freely and the cylinder motion is the direct result of the fluid dynamics action. For higher values of spring forces, the cylinder motion reaches a maximum displacement, and the spring forces induce the cylinder to an oscillatory movement damped by the fluid drag forces. Subsequently the amplitude of the displacement decreases. The cylinder motion is restricted within the mainstream fluid flow, where the maximum displacement reduces as the Reynolds number increases.
Procceedings of the 18th Brazilian Congress of Thermal Sciences and Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Computation
The immersed boundary method has attracted considerable interest in the last few years. The metho... more The immersed boundary method has attracted considerable interest in the last few years. The method is a computational cheap alternative to represent the boundaries of a geometrically complex body, while using a cartesian mesh, by adding a force term in the momentum equation. The advantage of this is that bodies of any arbitrary shape can be added without grid restructuring, a procedure which is often time-consuming. Furthermore, multiple bodies may be simulated, and relative motion of those bodies may be accomplished at reasonable computational cost. The numerical platform in development has a parallel distributed-memory implementation to solve the Navier-Stokes equations. The Finite Volume Method is used in the spatial discretization where the diffusive terms are approximated by the central difference method. The temporal discretization is accomplished using the Adams-Bashforth method. Both temporal and spatial discretizations are second-order accurate. The Velocity-pressure coupli...
Applied Mathematics and Computation
Procceedings of the 19th Brazilian Congress of Thermal Sciences and Engineering, 2022
American journal of heat and mass transfer, 2016
This paper presents a numerical study of fluid flow and natural convection inside cubical cavitie... more This paper presents a numerical study of fluid flow and natural convection inside cubical cavities using the finite volume method with second order schemes. Cubical cavities of various sizes with three different thermal configurations were considered, where two opposite vertical walls are isothermal and the other walls are either adiabatic or conducting (with linear temperature variation). The numerical simulations were performed for air and gases with Prandtl number 0.71 under the influence of variable Rayleigh numbers covering the range 10 3-10 7. The effects of the three thermal configurations in terms of velocities and temperatures were investigated for both steady and unsteady flow regimes. Additionally, the magnitudes of local and average Nusselt numbers in each direction of the cubical cavity were scrutinized. Using conducting walls, the heat transfer analysis in different directions divulged that the heat flow through the top/bottom walls surpasses 1/3 of the total heat flow of the cubical cavity. Overall, the collection of numerical results demonstrates good agreement when compared with experimental-based and numerical-based publications.
Procceedings of the 19th Brazilian Congress of Thermal Sciences and Engineering
XXVI Seminário de Iniciação Científica e Tecnológica da UTFPR, Oct 15, 2021
O objetivo deste trabalho e analisar a influencia do indice de Power Law na queda de pressao loca... more O objetivo deste trabalho e analisar a influencia do indice de Power Law na queda de pressao localizada de um escoamento em uma geometria de contracao abrupta. Para essa finalidade foi utilizado o software livre OpenFOAM, o escoamento foi modelado matematicamente com as equacoes de conservacao de massa, quantidade de movimento e o modelo de viscosidade de Power Law. O modelo numerico foi resolvido utilizando o metodo dos volumes finitos. Foram realizadas duas simulacoes variando o indice de Power Law. Foi concluido que na secao de contracao a queda de pressao do fluido com indice de Power Law maior e menos significativa e na regiao a jusante da contracao a queda de pressao do fluido com indice de Power Law maior e mais significativa.
No presente trabalho e simulado um problema de escoamento de fluido em uma contracao abrupta, que... more No presente trabalho e simulado um problema de escoamento de fluido em uma contracao abrupta, que e muito comum na geometria de brocas de perfuracao de pocos de petroleo. O fluido simulado e newtoniano e incompressivel e foi feita a simulacao de duas geometrias diferentes, um quarto de um tubo e uma fatia dessa geometria. E utilizada a metodologia dos volumes finitos para resolver as equacoes diferenciais na forma de equacoes algebricas. O software utilizado para a realizacao do trabalho foi o OpenFOAM , que e vantajoso por ser um software livre e codigo aberto. Por fim, sao apresentados resultados atraves de imagem em escala de cores e tambem da comparacao das curvas de velocidade para as duas malhas, e e avaliado a viabilidade da ferramenta Wedge do software OpenFOAM .
Neste trabalho, sao feitas analises dos dados de um modulo Peltier, construido com dissipador de ... more Neste trabalho, sao feitas analises dos dados de um modulo Peltier, construido com dissipador de calor, em uma caixa de poliestireno de 11x19x14 cm. Uma estimativa para o COP e a perda de calor no dispositivo de resfriamento termoeletrico tambem sao apresentados para diferentes configuracoes. As temperaturas foram medidas por sensores digitais que se apresentam em diferentes configuracoes por meio de uma fonte de alimentacao variavel.
Journal of the Brazilian Society of Mechanical Sciences and Engineering
The Canadian Journal of Chemical Engineering
Boundary Elements and other Mesh Reduction Methods XLII
A simplified fluid-structure interaction model, consisting of a cylinder tethered by a spring sys... more A simplified fluid-structure interaction model, consisting of a cylinder tethered by a spring system interacting dynamically with an incompressible two-dimensional lid-driven cavity flow, is solved using the immersed boundary method. Results show that when the spring forces are weaker than the fluid drag force, the springs stretch freely and the cylinder motion is the direct result of the fluid dynamics action. For higher values of spring forces, the cylinder motion reaches a maximum displacement, and the spring forces induce the cylinder to an oscillatory movement damped by the fluid drag forces. Subsequently the amplitude of the displacement decreases. The cylinder motion is restricted within the mainstream fluid flow, where the maximum displacement reduces as the Reynolds number increases.
Procceedings of the 18th Brazilian Congress of Thermal Sciences and Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Proceedings of the 25th International Congress of Mechanical Engineering
Computation
The immersed boundary method has attracted considerable interest in the last few years. The metho... more The immersed boundary method has attracted considerable interest in the last few years. The method is a computational cheap alternative to represent the boundaries of a geometrically complex body, while using a cartesian mesh, by adding a force term in the momentum equation. The advantage of this is that bodies of any arbitrary shape can be added without grid restructuring, a procedure which is often time-consuming. Furthermore, multiple bodies may be simulated, and relative motion of those bodies may be accomplished at reasonable computational cost. The numerical platform in development has a parallel distributed-memory implementation to solve the Navier-Stokes equations. The Finite Volume Method is used in the spatial discretization where the diffusive terms are approximated by the central difference method. The temporal discretization is accomplished using the Adams-Bashforth method. Both temporal and spatial discretizations are second-order accurate. The Velocity-pressure coupli...
Applied Mathematics and Computation