Processing of a CAD/CAE Jobs in grid Processing of a CAD/CAE Jobs in grid environment using Elmerenvironment using Elmer

Electronics Group,Physics Department,Faculty of Science,Ain Shams University,

MMohamed ohamed HHusseinussein A. A.RazikRazik

GRID Computing Group GRID Computing Group

LIT LABLIT LAB

Aim of the TaskAim of the Task

The aim of my task is to simulate a physical phenomena which is heat transfer by using Elmer software and execute this simulation on the grid and take the result from the grid to the PC via user interface.

What is Elmer?What is Elmer?Elmer is a finite element software package

for the solution of partial differential equation(s),dealing with multiphysical simulations.

The Elmer package contains solvers for a variety of mathematical models. The following list summarizes the capabilities of Elmer in specialized fields.

Physical models in ElmerPhysical models in Elmer• Heat transfer: models for conduction, radiation and phase

change• Fluid flow: the Navier-Stokes, Stokes and Reynolds equations,

k-" model• Species transport: generic convection-diffusion equation• Elasticity: general elasticity equations, dimensionally reduced

models for plates and shells• Acoustics: the Helmholtz equation• Electromagnetism: electrostatics, magnetostatics, induction• Micro fluidics: slip conditions, the Poisson-Boltzmann equation• Level set method: Euleri an free boundary problems• Quantum Mechanics: density functional theory (Kohn-Sham)

Numerical methods in ElmerNumerical methods in Elmer For approximation and linear system solution Elmer offers a

great number of possibilities. The following list summarizes some of the most essential ones.

• All basic element shapes in 1D, 2D and 3D with the Lagrange shape functions of degree k 2

• Higher degree approximation using p-elements• Time integration schemes for the first and second

order equations• Solution methods for Eigen value problems• Direct linear system solvers (Lapack & Umfpack)• Iterative Krylov subspace solvers for linear systems• ILU preconditioning of linear systems• Parallelization of iterative methods• The discontinuous Galerk in method• Stabilized finite element formulations, including the

methods of residual free bubbles and SUPG• Adaptively, particularly in 2D

IntroductioIntroduction to n to Message Passing Message Passing Interface (Interface (MPI)MPI) What is MPI?

◦ Message Passing Interface Message passing is a method by which data from one processor memory

is copied to another processor memory Why MPI?

◦ MPI library functions enable programmers to write portable codes, which can run on distributed-memory/shared memory multiprocessor machines cluster of workstations

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Parallel processingParallel processing

Parallel processing is the ability to carry out multiple operations or tasks simultaneously.

Parallel Processing in Computers The simultaneous use of more than one CPU

or processor core to execute a program or multiple computational threads. Ideally, parallel processing makes programs run faster because there are more engines (CPUs or cores) running it.

Parallel Implementation in ElmerParallel Implementation in Elmer

The general concept of a parallel run within Elmer is displayed in Figure .

Elmer uses domain decomposition for distributing the load to multiple processes that are being run on either different cores or CPUs. To that end, the initial mesh has to be split into parts that – with respect to the applied models – lead to similar loads of the processors.

Practice on Elmer software Practice on Elmer software The aim task is to run a simulation

experiment on the grid and this simulation is worked parallel and take the result and store it on the pc via user interface.

We have a physical problem heat transfer begins with certain boundary conditions after certain time we study the heat transfer.

Workflow to create Elmer file Workflow to create Elmer file Open your input file (example: samples/grd/angle3d.grd):

WorkflowWorkflowOptionally configure mesh generator and remesh:

WorkflowWorkflow The values in the config dialog are inherited from cmd line tools: As shown in special window

WorkflowWorkflowRemeshing is perfomed in a separate thread:

WorkflowWorkflow Manipulate boundaries: Select boundaries by holding down the CTRL-key

while double clicking. Choose ”unify surface” to join:

WorkflowWorkflowDefine an equation (PDE-system) to solve:As shown in special window

WorkflowWorkflow Let us define the ”heat equation” as an example: As shown in special window

WorkflowWorkflow Similarly, we can next define material properties and parameters: As shown in special window

WorkflowWorkflowAdd body force:

WorkflowWorkflowset boundary conditions:

WorkflowWorkflowGenerate solver input file (sif):

WorkflowWorkflowSave the model:

WorkflowWorkflowRun solver:

WorkflowWorkflow Convergence monitor reveals possible problems:

Processing of the data on the gridProcessing of the data on the grid

Job submissionJob submission of Elmer file to the gridof Elmer file to the grid

Job statusJob status

Retrieve job's outputRetrieve job's output

Transfer the result from the grid Transfer the result from the grid to the pc via interface.to the pc via interface.

WorkflowWorkflowVisualize the results by Elmer post:

Acknowledgement Acknowledgement

I would like to thank:Alexander UjhinskiyNikolay kutovskiy

For continuous efforts for teaching the aspects and completing the jobs of the grid. Thanks for sincerely help.

ANDThanks for supervisors of the school

for help and attentions.Prof.Dr.Ali Ellithi & Prof.Dr. Ali Khalil

Thank you for your Thank you for your attentionattention

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WorkflowWorkflow Edit the solver input file (if needed):

WorkflowWorkflow Turn on/off boundary index numbering for verification:

WorkflowWorkflowData is given in the ”General” and ”Heat equation”

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