2 www.cst.com Mar-09
Transient Thermal Solver
•Time domain simulations of thermal
processes.
•EMS/MWS coupling possible.
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Transient Thermal Solver
Features:
• Temperature-, heat-source (time dependent)
• External losses (pre-computed or imported Power
Loss from MWS / EMS / PS).
• Bioheat Model
• Isothermal, Adiabatic and open boundary condition
• 3D temperature monitor
• 1D function monitors (Energy, timestepping, ...)
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BioheatBoth thermal solvers are able to consider special properties of
biological material. These are the metabolic heat production of
human tissue and the heat exchange mechanism due to blood
perfusion.
The Human model
Voxel Dataset 2009
contains bioheat
material properties.
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Thermal Co-Simulation
between 2 different projects
www.cst.com
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Thermal coupling of 2 CST projects
via import of power loss distribution
+Different grids, boundaries/symmetries, material
properties possible
+Thermal structure parts can be added later on
+Changing thermal simulation properties (e.g.
Parameter sweep) will not delete EM-results.
First project: EM–simulation Second project: Stationary or
Transient thermal simulation
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Thermal Boundaries and Symmetries
In waveguide port planes as well as for magnetic Symmetry
Planes, typically adiabatic should be chosen
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Activate CST MWS losses as thermal sources
During S-Parameter Simulations
MWS monitors are normalized to
1W peak (=0.5 W rms) input power at
the port. This factor allows scaling to
the real applied input power.
Examples:
5 W rms factor = 10
500 W rms factor = 1000
2mW rms factor = 0.004
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CST MWS normalization of
result values
1) S-Parameter – Simulations: 1W peak input power
2) Eigenmode Simulations: 1J total stored energy in mode
3) plane wave simulations: specified electric field amplitude
(peak value)
4) discrete voltage or current port: specified current/voltage
amplitude (peak value)
simultaneous port excitations / combine results: final norming
results by multiplying the given amplitudes with the above
scaling (1-4)
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Particle – Thermal coupling
Particles loss distribution
can be used as a source for
the thermal solver
Particles hitting metal
produce loss distribution
Trajectory Temperature
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Transient Thermal Simulation
Induction Cooker
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Real World Example
www.cst.com
Courtesy by IMS Connector SystemsFor more details read
Article ID 373 on www.cst.com
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Measurement versus Simulation
www.cst.com
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Modeling Temperature Effects of RF
Thermoablation in a Human Liver
using the bioheat formulation
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Result
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For more details read
Article ID 387 on www.cst.com
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Summary / Outlook
• Thermal Solver is able to read power sources from:
• CST MWS – Monitor, calculated by T or F hex solver
• CST MWS - Eigenmode
• CST EMS - LF solver
• CST PS - absorbed power by hitting particles
• Thermal coupling of 2 CST projects
• Transient thermal solver (eg bioheat...)
• 2010-version: ability to read losses from FD-TET solver