High-Power Thermal Analysis using HFSS and ANSYS...
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High-Power Thermal Analysis using HFSS and ANSYS Mechanical Integration Martin Vogel, PhD Product Management Team
Transcript of High-Power Thermal Analysis using HFSS and ANSYS...
High-Power Thermal Analysis
using
HFSS and ANSYS Mechanical Integration
Martin Vogel, PhD
Product Management Team
Why couple simulators for electro-magnetics and multi-physics?
Courtesy of
Electronics produce heat, which can cause malfunctions.
Existing Electromagnetics – Multiphysics Links
Electromagnetic simulators:
HFSS, Q3D Maxwell SIwave
ANSYS Mechanical
Thermal Solvers
ANSYS ICEPAK
cooling of
electronics
ANSYS FLUENT
Thermodynamics
and fluid flow
ANSYS Mechanical
Stress Solver
Raytheon high-power connector
Co-axial Glass + Micro-strip Metal
cable Kovar trace housing
Before turning power on
Courtesy of
Co-axial pin connecting to microstrip trace
Soon after turning power on
Courtesy of
Excessive heat has destroyed the connector.
HFSS has been “data integrated” with Workbench
Analyze the model in HFSS
Pin connecting to trace
Easy to link to thermal simulators
Add boundary conditions for convection and cooling.
Natural convection
Cooling on bottom face
Outline of thermal model
Temperature exceeds 300 deg C in kovar.
Link thermal to structural analysis
Resulting schematic
Deformation up to 22 µm
Stress mostly in inner conductor
Improve the design.
• Kovar, responsible for the high temperatures, has been replaced by a different metal.
• Temperatures may still be high, which Teflon cannot handle. Accurate analysis
wanted.
• Use the two-way thermal coupling to account for temperature-dependent materials.
Why two-way thermal?Teflon loss tangent increases with temperature. Run-away effect possible.
Glass transition
Two-way thermal link
Solve EM model at initial temperature.
Send electromagnetic
loss to thermal simulator.
Determine temperatures.
Send temperatures back to EM model.
Material parameters change.
Solve EM model with
new temperatures.
ΔT < threshold?
Done
NoYes
Two-way thermal analysis: Final temperatures with normal Teflon
EM Power Losses as function of two-way thermal iteration
Volume Loss in normal Teflon
Surface Loss on metals
Volume Loss in low-loss Teflon
Temperatures as function of two-way thermal iteration
Tmax Normal Teflon
Tmax Low-Loss Teflon
Tmin Normal Teflon
Tmin Low-Loss Teflon
Two-way thermal analysis:
Final temperatures with low-loss Teflon
