CST SPACE APPLICATIONS WORKSHOP · CST – COMPUTER SIMULATION TECHNOLOGY | i i i nm nm D MWS p p S S S ' w w (3 ) ¦. What is it good for? The sensitivity helps estimate „new“

CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com

CST SPACE APPLICATIONS WORKSHOP


September 23, 2014 Toulouse, France

For more information,

please visit: www.cst.com

AGENDA MW & RF ANTENNA SESSION

MW & RF COMPONENT SESSION

EMC ON SATELLITES

MULTIPHYSICS APPLICATIONS


Thermal Effects and

Deformation


Franz Hirtenfelder

CST AG


• Motivation

• Test Vehicle

• Single Components

• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


EM-field computation

Thermal

analysis

Stress analysis /

deformation

EM-properties of deformed geometry

can be fed into sensitivity analysis

Motivation


CST MPHYSICS STUDIOTM

Thermal Simulation

Mechanical Stress Simulation


• Motivation

• Test Vehicle


• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


Testvehicle

PowerSplitter Ku Band

Cascaded Type (Single Splitter 1:4, Output -6,-7,-2.6 dB) + 2 Highpasses + 1 Lowpass

Returnloss < -25dB

Lp

Hp


Lowpass Filter (corrugated)

Optimized cavity lengths and irises


Goals, S-Parameters


Highpass Filter (stepped)

Optimized waveguide sections and lenghts


Goals and S-Parameters


Splitter Optimized coupling widths and distances


1D Results > S-Parameters


Optimizer Details


WG Bend


• Motivation

• Test Vehicle


• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


CST DesignStudio


CST DesignStudio


• Motivation

• Test Vehicle


• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


CST MWS !T


CST MWS !T


Ports


1D Results > S-Parameters


• Motivation

• Test Vehicle


• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


Imported Losses

Thermal Surface Losses


343K 323K

Boundary Conditions

floating

adiabatic

adiabatic

adiabatic

Thermal open boundaries

Konst. Temp. faces


2D/3D Results >

Heat Flow Density [THs]

Temperature [THs]


• Motivation

• Test Vehicle


• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


Mechanical Simulation

Displacements fixed at both port-sides


2D/3D Results > Displacements


2D/3D Results > Stress > Von Mises

1 Gigapascal [GPa] = 1.000 kN/mm²

Ultimate Tensile Strength (ALU)= 0.111GPa

(110N/mm2 = 11kp/mm2), (Steel ST37 = .37GPa)


• Motivation

• Test Vehicle


• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


CST MWS !T (+ mech. Sensitivity)


),(),(),(1

),(0

pEpKpEj

pS TT

Introduction to Sensitivity

S-Parameters:

[K] …left hand side, E (Fields at ports, p… any parameter

Ep

KE

p

Sj T

0

Sensitivity of S-parameter vs. parameter change:

Direct analytical derivation of

K-matrix elements via e.g. [N]

3D Fieldsolution

Same 3D Fieldsolution


i

i i

MWSDnmnm pp

SSS

.)3(

What is it good for?

The sensitivity helps estimate „new“ S-parameters due to the (small)

change of the parameter, at no extra cost

Suppose the parameter p changes by a quantity ∆p :

exact computation of the Sensitivity

(Approximated by 1st order Taylor expansion)


The various sensitivities are used in an optimizer to solve for ∆p as variables to

best fit the S-parameter goals. ∆p … face constraints

i

i i

pp

SxSpxS

.)()(


S-Parameter Sensitivity

> mechField > |S| linear


1D Results > Comparison


1D Results > Comparison


• Motivation

• Test Vehicle


• Complete Model

• EM

• Thermal

• Mechanical

• EM

• Summary

Overview


Summary

Integrated workflow with

CST MPHYSICS STUDIO™

Ease-of-use: New solvers within

well known frontend

Accuracy of integrated solution and solver

technology

Wide application range due to tight

integration within CST STUDIO SUITE™

Thermal

Structural Mechanics

EM


Thermal Effects and

Deformation


Thank you!

Any questions?


Appendix



Matrix to solve: QEK

[K]: symmetric, complex, contains geometry, material, frequency

xi, yi

Example: Linear Shape functions for a 2D element in xy

jkijkkjijkkjkjijk

kji

kji

kji

xxcyybxyyxa

ccc

bbb

aaa

yxN

;;;.,,1

2

1

xj, yj

xk, yk

k

j

i

kji

z

z

z

NNNz ],,[

zi

[E]: unkowns z

[Q]: Sources

kjinmdxdyx

N

x

N

x

N

x

Nk nm

ynm

xy

xnm ,,,;)(,

Example: electrostatic


FxKxBxM


http://www.engineeringtoolbox.com/young-modulus-d_417.html

1 GPa = 1kN/mm2 σ=ε.E



Elast. modul


Therm conductivity



Power Splitter

Documents

CST SPACE APPLICATIONS WORKSHOP · CST – COMPUTER SIMULATION TECHNOLOGY | i i i nm nm D MWS p p S S S ' w w (3 ) ¦. What is it good for? The sensitivity helps estimate „new“