Multiphysics Modeling in FEMLAB 2.2

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Multiphysics ModelinginFEMLAB 2.2

• Fall 2001
• COMSOL

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Contents

• Introduction
• Modeling in FEMLAB
• A first simple model of direct current conduction
• Influence of wave guide geometry on wave
  propagation
• 3D Electromagnetics
• Reaction distribution in a monolithic reactor
• Chemical engineering and transport phenomena
• Study of the stresses in a guyed mast
• Preview of the upcoming structural mechanics
  module
• Support and courses

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Why modeling ?

• Education
• Accelerates understanding
• Saves time and money
• Rapid prototyping
• Safety
• Spares equipment
• Fun?

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Our company

• Founded in 1986 by two Ph.D. Students at the
  Royal Institute of Technology
• Developed several products within the Matlab
  family
• 95 employees in offices in Sweden, Finland,
  Norway, Denmark, USA, Germany, UK and France
• We want to provide user-friendly and powerful
  software for modeling in education, research,
  design, and development

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Our first FEMLAB model

• Shows the main steps of the modeling process in
  FEMLAB
• Highlights
• Single physics
• 2D and 3D drawing tools
• Several subdomains with different properties
• Post processing including boundary integration
• M-file features

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Problem definition
Outflow 1
Ñ(-k ÑV) 0
V 0
V 0
k3
Outflow 2
k2
k1
V 1
How is the current distributed between outflows 1
and 2 ?
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Results
Integrate current density
Integrate current density
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Summary of the modeling process

• Draw Mode
• Boundary Mode
• Subdomain Mode
• Mesh Mode
• Post Mode

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Study of waveguide geometry in 3D

• How does the geometry influence the reflection of
  the wave?
• How is the mode of the traveling wave changed in
  the waveguide ?
• Exemplifies the use of FEMLAB in prototyping
• Shows the new 3D Electromagnetics Module

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Problem definition
Ñx(ÑxE) - k2E 0
Transmitted wave
nx(ÑxE) ikEt 2ikEinc
Incoming wave
Is there a change in mode ? What is the
dependency between the frequency and the
reflection coefficient?
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Results
In
Out
propagating wave
standing wave
A frequency of 8.1 GHz gives minimal reflection,
7 The incoming TE11-mode is transformed to a
TE10-wave
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Results S-parameters
S212
minimal reflection
Frequency (Hz)
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Results S-parameters

• The S-parameter S21 (for open-ends) is
• This can be computed as boundary integrals in the
  FEMLAB GUI

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Reaction distribution in a monolithic reactor

• To which extent is the catalyst utilized ?
• How will the catalyst degrade due to temperature
  effects ?
• Exemplifies the use of FEMLAB in chemical
  reaction engineering design
• Shows the new version of the chemical engineering
  module

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Problem definition
Outlet
Ñ (-DÑc) kc 0
Porouscatlyst
Ñ (-DÑc cv) 0
Free fluid
Inlet
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Results

• Substantial depletion within the catalyst at a
  given z-position
• Utilization of the catalyst is not optimal
• Depletion along the z-axis gives a fairly good
  reactor performance

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Socket for a guyed mast

• Minimize transport and material costs
• Minimize weight and maximize mechanical strength
• Study the distribution of stresses in a suggested
  design
• Decide if we should pursue the work based upon
  the suggested design, which implies a
  displacement below 0.1 mm at the thinnest part

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Socket in a guyed mast
Guyed mast for telecom
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Problem definition
¼ is modeled due to symmetry
symmetry
symmetry
z
P
Naviers equations
no displacement in z-direction
2u
r
-Ñc Ñu K
t2
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Results
Von Misses stresses and displacement
max stress
Maximum stress and displacement
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Support courses

• Experienced engineering staff
• Searchable FAQ database
• Extensive technicalsupport_at_femlab.com
• Download minicourse, apply for on-site minicourse
  or attend to our courses
• Developer Zone

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Next step

• Download white papers, articles product sheets
  etc.
• Try FEMLAB yourself at hands-on seminars or
  trials
• Apply for on-site seminars and hands-on seminars
• Run tutorials and models at www.femlab.com