Transcript Introduction_to_Comsol

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COMSOL 4.3
 Remote Connection
http://www.che.utah.edu/wpcms/?page_id=308
 Chemical Engineering Department (ICC)
 Login and password
Ask IT staff at chemical engineering department
(801) 5857170
[email protected]
COMSOL -Remote Connection
 Windows user
To launch remote desktop
START-->
RUN--> type "mstsc.exe"
“Or in Vista”
Start -->
All Programs -->
Accessories --> Remote Desktop Connection
Use your ICC login and password.
You will be connected remotely to ICC machines
 Mac or Linux user
Search for the software you need on line
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terminal-1.chemeng.utah.edu
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Connecting with Windows 7
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Connecting from OSX (Tested on 10.8)
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Connecting from Windows XP
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COMSOL-4.3
www.comsol.com
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Background and applications of COMSOL
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Free Webinar: http://www.comsol.com/events/webinars/
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Free tutorial CDs
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Updated information
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COMSOL Application
You can use COMSOL Multiphysics in many application
areas, just a few examples being:
▫ Chemical reactions
▫ Diffusion
▫ Fluid dynamics
▫ Fuel cells and electrochemistry
▫ Bioscience
▫ Acoustics
▫ Electromagnetics
▫ Geophysics
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COMSOL Application
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Heat transfer
Microelectromechanical systems (MEMS)
Microwave engineering
Optics
Photonics
Porous media flow
Quantum mechanics
Radio-frequency components
Semiconductor devices
Structural mechanics
Transport phenomena
Wave propagation
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The COMSOL Modules
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AC/DC Module
Acoustics Module
Chemical Engineering Module
Electrochemistry
Fluid flow
Heat transfer
Plasma
Radio frequency
Structural mechanics
Mathematics
The optional modules are optimized for specific application areas. They offer discipline
standard terminology and interfaces, materials libraries, specialized solvers, elements, and
visualization tools.
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The Chemical Engineering Module
The Chemical Engineering Module presents a powerful way of
modeling equipment and processes in chemical engineering.
It provides customized interfaces and formulations for
momentum, mass, and heat transport coupled with chemical
reactions for applications such as:
▫ Reaction engineering and design
▫ Heterogeneous catalysis
▫ Separation processes
▫ Fuel cells and industrial electrolysis
▫ Process control together with Simulink
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The Chemical Engineering Module …
COMSOL Multiphysics excels in solving systems of coupled
nonlinear PDEs that can include:
▫ Heat transfer
▫ Mass transfer through diffusion and convection
▫ Fluid dynamics
▫ Chemical reaction kinetics
▫ Varying material properties
The multiphysics capabilities of COMSOL can fully couple and
simultaneously model fluid flow, mass and heat transport, and
chemical reactions.
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The Chemical Engineering Module …
In fluid dynamics you can model fluid flow through porous media
or characterize flow with the Navier-Stokes equations.
It is easy to represent chemical reactions by source or sink terms
in mass and heat balances.
All formulations exist for both Cartesian and Cylindrical
coordinates (for axisymmetric models) as well as for stationary
and time-dependent cases.
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The Chemical Engineering Module …
The available application modes are:
1. Momentum balances
▫ Incompressible Navier-Stokes equations
▫ Darcy’s law
▫ Brinkman equations
▫ Non-Newtonian flow
▫ Nonisothermal and weakly compressible flow
▫ Turbulent flow, k-ε turbulence model
▫ Turbulent flow, k-ω turbulence model
▫ Multiphase flow
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The Chemical Engineering Module …
2. Energy balances
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Heat conduction
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Heat convection and conduction
3. Mass balances
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Diffusion
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Convection and diffusion
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Electrokinetic flow
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Maxwell-Stefan diffusion and convection
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Nernst-Planck transport equations
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The Modeling Process
The modeling process in COMSOL consists of six main steps:
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Selecting the appropriate application mode in the Model
Navigator.
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Drawing or importing the model geometry in the Draw
Mode.
3. Setting up the subdomain equations and boundary conditions
in the Physics Mode.
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Meshing in the Mesh Mode.
5. Solving in the Solve Mode.
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Postprocessing in the Postprocessing Mode.
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1. The Model Navigator
When starting COMSOL Multiphysics, you are greeted by the
Model Navigator. Here you begin the modeling process and
control all program settings. It lets you select space dimension
and application modes to begin working on a new model, open
an existing model you have already created, or open an entry in
the Model Library.
COMSOL Multiphysics provides an integrated graphical user
interface where you can build and solve models by using
predefined physics modes
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2. Creating Geometry
An important part of the modeling process is creating the
geometry. The COMSOL Multiphysics user interface contains
a set of CAD tools for geometry modeling in 1D, 2D, and 3D.
The CAD Import Module provides an interface for import of
Parasolid, SAT (ACIS), STEP, and IGES formats.
In combination with the programming tools, you can even use
images and magnetic resonance imaging (MRI) data to create a
geometry.
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Axes and Grid
In the COMSOL Multiphysics user interface you can set limits
for the model axes and adjust the grid lines. The grid and axis
settings help you get just the right view to produce a model
geometry. To change these settings, use the Axes/Grid
Settings dialog box that you open from the Options menu.
You can also set the axis limits with the zoom functions.
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Axes and Grid
The default names for coordinate systems vary with the space
dimension:
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Models that you open using the space dimensions 1D, 2D,
and 3D use the Cartesian coordinates x, y, and z.
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In 1D axisymmetric geometries the default coordinate is r,
the radial direction. The x-axis represents r.
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In 2D axisymmetric geometries the x-axis represents r, the
radial direction, and the y-axis represents z, the height
coordinate.
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3. Modeling Physics and Equations
From the Physics menu you can specify all the physics and
equations that define a model including:
▫ Boundary and interface conditions
▫ Domain equations
▫ Material properties
▫ Initial conditions
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4. Creating Mesh
When the geometry is complete and the parameters are defined,
COMSOL Multiphysics automatically meshes the geometry.
However, you can take charge of the mesh-generation process
through a set of control parameters.
For a 2D geometry the mesh generator partitions the subdomains
into triangular or quadrilateral mesh elements.
Similarly, in 3D the mesh generator partitions the subdomains
into tetrahedral, hexahedral, or prism mesh elements.
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5. Solution
Next comes the solution stage. Here COMSOL Multiphysics
comes with a suite of solvers for stationary, eigenvalue, and
time-dependent problems.
For solving linear systems, the software features both direct and
iterative solvers. A range of preconditioners are available for
the iterative solvers. COMSOL sets up solver defaults
appropriate for the chosen application mode and automatically
detects linearity and symmetry in the model.
A segregated solver provides efficient solution schemes for large
multiphysics models, turbulence modeling, and other
challenging applications.
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6. Postprocessing
For postprocessing, COMSOL provides tools for plotting and
postprocessing any model quantity or parameter:
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Surface plots
Slice plots
Isosurfaces
Contour plots
Arrow plots
Streamline plots and particle tracing
Cross-sectional plots
Animations
Data display and interpolation
Integration on boundaries and subdomains
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Report Generator
To document your models, the COMSOL Report Generator
provides a comprehensive report of the entire model,
including graphics of the geometry, mesh, and postprocessing
quantities.
You can print the report directly or save it as an HTML file for
viewing through a web browser and further editing.
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COMSOL -Example
Flow Past the Cylinder
Getting Started
Comsol Multiphysics 4.2
Must be known
Properties of the fluid/material
Objective of the problem
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Example: Flow Past a Cylinder- Benchmark test for CFD algorithms
Unsteady, incompressible flow
Wake formationUnordered eddies
Large drag on body
Cylinder: Off center, otherwise steady state symmetric flow
Objective : Frequency and amplitude of vibration (Forces) at various fluid speed
Reynolds # based on cylinder diameter
1. Slow flow (below Re # 100) -steady flow (start with this to correct simple errors and
mistakes)
2. Fast flow - (Re # = 100)- developed Von Karman vortex street (not fully
turbulence)
(time dependent simulation)
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Select Space Dimension:
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Select Mode:
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Define the parameters:
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Geometry, Material and Boundary:
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Rectangle 1
1 In the Model Builder window, right-click Model 1>Geometry 1 and
choose Rectangle.
2 Go to the Settings window for Rectangle.
3 Locate the Size section. In the Width edit field, type 2.2.
4 In the Height edit field, type 0.4.
Circle 1
1 In the Model Builder window, right-click Geometry 1 and choose Circle.
2 Go to the Settings window for Circle.
3 Locate the Position section. In the x edit field, type 0.2.
4 In the y edit field, type 0.2.
5 Locate the Size and Shape section. In the Radius edit field, type 0.05.
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Difference 1
1 Right-click Geometry 1 and choose Difference.
2 Go to the Settings window for Difference.
3 Locate the Difference section. Under Objects to add, click Activate Selection.
4 Select the object r1 only.
5 Under Objects to subtract, click Activate Selection.
6 Select the object c1 only.
7 In the Model Builder window, right-click Geometry 1 and choose Build All.
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MATERIALS
Material 1
1 In the Model Builder window, right-click Model 1>Materials and choose Material.
2 Go to the Settings window for Material.
3 Locate the Material Contents section. In the Material contents table, enter the
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Inlet 1
1 In the Model Builder window, right-click Model 1>Laminar Flow and choose Inlet.
2 Select Boundary 1 only.
3 Go to the Settings window for Inlet.
4 Locate the Velocity section. In the U0 edit field, type
U_mean*6*s*(1-s)*step1(t[1/s]).
Outlet 1
1 In the Model Builder window, right-click Laminar Flow and choose Outlet.
2 Select Boundary 4 only.
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MESH :
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In the Model Builder window, click Model 1>Mesh 1.
Go to the Settings window for Mesh.
Locate the Mesh Settings section. From the Element size list, select Finer.
Click the Build All button.
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Step 1: Time Dependent
1 In the Model Builder window, expand the Study 1 node, then click Step 1: Time Dependent.
2 Go to the Settings window for Time Dependent.
3 Locate the Study Settings section. In the Times edit field, type range(0,0.2,3.4) range(3.5,0.02,7).
4 In the Model Builder window, right-click Study 1 and choose Show Default Solver.
5 Expand the Study 1>Solver Configurations node
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Solver 1
1 In the Model Builder window, expand the Study 1>Solver Configurations>Solver 1
node, then click Time-Dependent Solver 1.
2 Go to the Settings window for Time-Dependent Solver.
3 Click to expand the Time Stepping section.
4 From the Steps taken by solver list, select Intermediate.
5 In the Model Builder window, right-click Study 1 and choose Compute.
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Solver
Karman path
Fully developed flow
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Velocity:
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Pressure:
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Post Processing (Particle Tracing)!!!!!!!:
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Any Question