Simulação numérica de escoamentos viscoelásticos multifásicos complexos

Figueiredo, Rafael Alves

doi:10.11606/t.55.2016.tde-30112016-160821

“…In this sense, an advection algorithm with a fractional step (split) was implemented. This technique simplifies the method and prevents the transportation of the same fluid portion twice, as happens in single-step (unsplit) methods [20].…”

Section: Governing Equationsmentioning

confidence: 99%

“…Thus, three consecutive updates are needed to carry f at each time step, i.e., f n → f * → f * * → f n+1 . Thus, discretizing f implicitly on the right-hand side of Equation (19), implicitly on the right-hand side of Equation (20), and explicitly on the right-hand side of Equation ( 21) leads to…”

Section: Interface Advectionmentioning

confidence: 99%

Validation of HiG-Flow Software for Simulating Two-Phase Flows with a 3D Geometric Volume of Fluid Algorithm

Silva,

Fernandes,

Organista

et al. 2023

Mathematics

0

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This study reports the development of a numerical method to simulate two-phase flows of Newtonian fluids that are incompressible, immiscible, and isothermal. The interface in the simulation is located and reconstructed using the geometric volume of fluid (VOF) method. The implementation of the piecewise-linear interface calculation (PLIC) scheme of the VOF method is performed to solve the three-dimensional (3D) interface transport during the dynamics of two-phase flows. In this method, the interface is approximated by a line segment in each interfacial cell. The balance of forces at the interface is accounted for using the continuum interfacial force (CSF) model. To solve the Navier–Stokes equations, meshless finite difference schemes from the HiG-Flow computational fluid dynamics software are employed. The 3D PLIC-VOF HiG-Flow algorithm is used to simulate several benchmark two-phase flows for the purpose of validating the numerical implementation. First, the performance of the PLIC implementation is evaluated by conducting two standard advection numerical tests: the 3D shearing flow test and the 3D deforming field test. Good agreement is obtained for the 3D interface shape using both the 3D PLIC-VOF HiG-Flow algorithm and those found in the scientific literature, specifically, the piecewise-constant flux surface calculation, the volume of fluid method implemented in OpenFOAM, and the high-order finite-element software FEEL. In addition, the absolute error of the volume tracking advection calculation obtained by our 3D PLIC-VOF HiG-Flow algorithm is found to be smaller than the one found in the scientific literature for both the 3D shearing and 3D deforming flow tests. The volume fraction conservation absolute errors obtained using our algorithm are 4.48×10−5 and 9.41×10−6 for both shearing and deforming flow tests, respectively, being two orders lower than the results presented in the scientific literature at the same level of mesh refinement. Lastly, the 3D bubble rising problem is simulated for different fluid densities (ρ1/ρ2=10 and ρ1/ρ2=1000) and viscosity ratios (μ1/μ2=10 and μ1/μ2=100). Again, good agreement is obtained for the 3D interface shape using both the newly implemented algorithm and OpenFOAM, DROPS, and NaSt3D software. The 3D PLIC-VOF HiG-Flow algorithm predicted a stable ellipsoidal droplet shape for ρ1/ρ2=10 and μ1/μ2=10, and a stable cap shape for ρ1/ρ2=1000 and μ1/μ2=100. The bubble’s rise velocity and evolution of the bubble’s center of mass are also computed with the 3D PLIC-VOF HiG-Flow algorithm and found to be in agreement with those software. The rise velocity of the droplet for both the ellipsoidal and cap flow regime’s is found, in the initial stages of the simulation, to gradually increase from its initial value of zero to a maximum magnitude; then, the steady-state velocity of the droplet decreases, being more accentuated for the cap regime.

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“…Para determinar o fluxo através da faceta em que o campo de velocidade está direcionado, deve-se utilizar informações geométricas obtidas no passo de reconstrução do PLIC-VOF. De acordo com Figueiredo (2016), a acurácia na resolução da equação (4.4) está diretamente ligada à precisão do método de reconstrução. No presente projeto, o passo de reconstrução foi feito como descrito na seção 4.4.1.…”

Section: Advecção Da Interfaceunclassified

“…Essa estratégia torna o método mais simples e evita que uma mesma porção de fluido seja advectada duas vezes, como ocorre nos métodos de passo único (FIGUEIREDO, 2016). De acordo com Puckett et al (1997), alternando-se a direção de advecção em cada passo de tempo, esse algoritmo atinge segunda ordem de precisão no tempo.…”

Section: Advecção Da Interfaceunclassified

Desenvolvimento da técnica PLIC-VOF no sistema HiG-Flow para simulação de escoamentos bifásicos

Silva¹

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The purpose of this master thesis was to study and implement numerical techniques for the computational simulation of incompressible, immiscible and isothermal two-phase flows of Newtonian fluids. In two-phase flows, a consistent description of the interface between fluids is very important to ensure accurate numerical simulation. The volume of fluid (VOF) method was used to locate and reconstruct the interface. The continuum interfacial force (CSF) model was considered for the balance of forces at the interface. Navier-Stokes equations were solved using the HiG-Flow solver, in which the VOF method was coupled. For the analysis of numerical results, the implemented methods were verified using data and classical problems of the literature, and proved to be consistent.

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Validation of HiG-Flow Software for Simulating Two-Phase Flows with a 3D Geometric Volume of Fluid Algorithm

Silva,

Fernandes,

Organista

et al. 2023

Preprint

0

View full text Add to dashboard Cite

This study reports the development of a numerical method to simulate two-phase flows of Newtonian fluids that are incompressible, immiscible, and isothermal. The interface in the simulation was located and reconstructed using the geometric volume of fluid (VOF) method. The implementation of the Piecewise-Linear Interface Calculation (PLIC) scheme of the VOF method was performed to solve the three-dimensional (3D) interface transport during the dynamics of two-phase flows. In this method, the interface is approximated by a line segment in each interfacial cell. The balance of forces at the interface was accounted for using the continuum interfacial force (CSF) model. To solve the Navier-Stokes equations, meshless finite difference schemes from the HiG-Flow computational fluid dynamics software were employed. The 3D PLIC-VOF HiG-Flow algorithm was used to simulate several benchmark two-phase flows for the purpose of validating the numerical implementation. First, the performance of the PLIC implementation was evaluated by conducting two standard advection numerical tests: the 3D shearing flow test and the 3D deforming field test. Good agreement is obtained for the 3D interface shape using both the 3D PLIC-VOF HiG-Flow algorithm and those found on the scientific literature. In addition, the absolute error of the volume tracking advection calculation obtained by our 3D PLIC-VOF HiG-Flow algorithm was found to be smaller than the one found in the scientific literature for both the 3D shearing and 3D deforming flow tests. Lastly, the 3D bubble rising problem was simulated for different fluid densities and viscosity’s ratios. Again, good agreement is obtained for the 3D interface shape using both the newly implemented algorithm and the OpenFOAM, DROPS and NaSt3D software. The bubble’s rise velocity and evolution of the bubble’s center of mass is also computed with the 3D PLIC-VOF HiG-Flow algorithm and found to be in agreement with these software.

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Simulação numérica de escoamentos viscoelásticos multifásicos complexos

Cited by 3 publications

References 126 publications

Validation of HiG-Flow Software for Simulating Two-Phase Flows with a 3D Geometric Volume of Fluid Algorithm

Validation of HiG-Flow Software for Simulating Two-Phase Flows with a 3D Geometric Volume of Fluid Algorithm

Desenvolvimento da técnica PLIC-VOF no sistema HiG-Flow para simulação de escoamentos bifásicos

Validation of HiG-Flow Software for Simulating Two-Phase Flows with a 3D Geometric Volume of Fluid Algorithm

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