Finite difference method for two-phase obstacle problem

In this study, SPMD parallel computation of compressible turbulent jet flow with an explicit finite difference method by direct numerical method is performed on the IBM Linux Cluster. The conservation equations, boundary conditions including NSCBC (charactering boundary conditions), grid generation method, and the solving processing are carefully presented in order to give other researchers a clear understanding of the large scale parallel computing of compressible turbulent flows using explicit finite difference method, which is scarce in the literatures. The speedup factor and parallel computational efficiency are presented with different domain decomposition methods. In order to use our explicit finite method for large scale parallel computing, the grid size imposed on each processor, the speedup factor, and the efficiency factor should be carefully chosen in order to design an efficient parallel code. Our newly developed parallel code is quite efficient from that of implicit finite difference method or spectral method on parallel computational efficiency. This is quite useful for future research for gas and particle two-phase flow, which is still a problem for highly efficient code for two-phase parallel computing.

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Comparative numerical study of single and two-phase models of nanofluid liquid film evaporation in a vertical channel

MATEC Web of Conferences ◽

10.1051/matecconf/202030701034 ◽

2020 ◽

Vol 307 ◽

pp. 01034 ◽

Cited By ~ 1

Author(s):

Monssif Najim ◽

M’barek Feddaoui ◽

Abderrahman Nait Alla ◽

Adil Charef

Keyword(s):

Mass Transfer ◽

Finite Difference ◽

Finite Difference Method ◽

Liquid Film ◽

Heat And Mass Transfer ◽

Difference Method ◽

Single Phase ◽

Vertical Channel ◽

Two Phase ◽

Phase Models

The main purpose of this study is to survey numerically comparison of two-phase and single-phase models of heat and mass transfer of Al2O3-water nanofluid liquid film flowing downward a vertical channel. A finite difference method is developed to produce the computational predictions for heat and mass transfer during the evaporation of the liquid film approached by the single-phase and two-phase models. The model solves the coupled governing equations in both nanofluid and gas phases together with the boundary and interfacial conditions. The systems of equations obtained by using an implicit finite difference method are solved by Tridiagonal Matrix Algorithm. The results show that the two-phase model is more realistic since it takes into account the thermophoresis and Brownian effects.

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Towards modelling magmatic systems using a staggered grid finite difference method

10.5194/egusphere-egu21-4271 ◽

2021 ◽

Author(s):

Nicolas Berlie ◽

Boris Kaus ◽

Anton Popov ◽

Mara Arts ◽

Nicolas Riel ◽

...

Keyword(s):

Finite Difference ◽

Finite Difference Method ◽

Difference Method ◽

Stokes Equations ◽

Numerical Models ◽

Geophysical Methods ◽

Resolving Power ◽

Staggered Grid ◽

Two Phase ◽

Advection Schemes

The dynamics of magmatic systems remain poorly understood, due to the lack of resolving power of geophysical methods to study active systems and the difficulty of interpreting exposed crystallized magma bodies. Numerical models are therefore helpful to connect the dots between classical geological studies, using rheological information and geometries derived from field or geophysical investigations to shed new lights on the mechanisms involved in such systems.Taking advantage of the big CPU clusters currently available and the development of the DMStag framework as part of the PETSc infrastructure, the ERC-funded MAGMA project aims to build tools to analyse magmatic processes in the lithosphere. We developed a finite-difference staggered grid code solving the Stokes equations for visco-elasto-plastic rheologies and using analytical jacobians for linear and non-linear solvers, combined with regularized plasticity. The code is combined with both a marker and cell and semi-lagrangian advection schemes, is fully parallel and includes automated testing.Here, we provide application examples ranging from simple benchmark validations against analytical solutions to more complex settings taking advantage of the broad rheologies and local heterogeneities permitted by high resolution settings and the finite difference method. Ongoing technical developments include adding two-phase flow and coupling to it with thermodynamic calculations to track the evolving chemistry of magmatic systems.

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