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Thermica : Overview and New Features – 19th European Workshop on Thermal and ECLS Software

Thermica :Thermica :Overview and New FeaturesOverview and New Features

TimothéeTimothée SORIANOSORIANOMarc JACQUIAUMarc JACQUIAU

Philippe CHEOUXPhilippe CHEOUX--DAMASDAMAS

Page 2 Thermica : Overview and New Features – 19th European Workshop on Thermal and ECLS Software

Thermica: Overview and New Features19th European Workshop on Thermal and ECLS Software

Content

Geometry

Mission

Radiation

Conduction

Temperature Solver

Temperature Mapping

Post-processing


Introduction

Current release: Thermica v.3.2.20 (August 2005)

New modeler T4Star

New conduction module

ThermiSol (temperature solver) v.4.0.29

Many other features

Next release: Thermica v.3.2.21 (March 2006)

Extended Mission

Extended radiation

Temperature Mapping

Posther (new ThermiSol post-processing)

And all presented features

V4 release (November 2006)

Extended T4star modeler with application data management

New environment for all applications and visualizations


Geometry: operational tool for model managementT3D interactive modeler

Creation and Edition of Objects, Shapes and Meshes

Interactive shape creation, copy/paste, translation/rotation

Hierarchy, numbering, …

Display of properties & results in 3D

Creation and Edition of Properties

Material Database

Physical Properties

Optical Properties

Ray tracing Properties

Equivalent of Sysbas language

T3DT3D


Geometry: additional tool for CAD importT4Star

New Import Capabilities

from CAD Model (STEP)

from Bulk Nastran (BLK)

Semi-automatic simplification

Quick shape construction

Help items

(grids, specific points…)

Advanced visualization features

Easy 3D Manipulation

Multi-viewers management

Multi-models management

Full interactivity with the browser and the geometry

T4StarT4Star


MissionClassical orbit and pointing

The mission module of Thermica is adapted to classical orbits

Classical pointing can be defined

Several pre-defined directions

Attitude laws (yaw, pitch, roll)

Moving bodies (antennas, panels, …) with 1 or 2 dof

Geostationary Orbit(GEO)

TelecommunicationsMeteorology

36 000 km :

Low Earth Orbits(LEO)

200 - 400 km :

400 - 900 km :

Manned flights

Earth ObservationMeteorologyScientific Missions

Medium Earth Orbits(MEO)

Telecom constellations1000 - 5000 km :

Navigation20000 km :


MissionComplex kinematics

Option 1: an attitude law can be defined in a ASCII file

Definition of yaw, pitch, roll by regard with the standard pointing directive

Option 2: an arbitrary kinematics can be defined in an ASCII file

Definition of rotation matrices for the satellite & moving bodies in the Earth

gamma 50 frame

Option 3 : the system reference, or a mobile part, can be pointed to an external orbit (ex: communication between satellites)

1st pointingdirection

2nd pointingdirection

PitchYaw

Roll

Julian day yaw pitch rollJulian day yaw pitch roll


Mission (available 2006)Trajekin module

TRAJEKIN : a new module to import external trajectories and kinematics (when the mission is not a classical Thermica orbit)

A need expressed by launcher prime companies + other specific firms

The user starts from a trajectory & kinematics described in a tabulated asciifile, calculated by another processMost of the classical conventions taken into account and translated in Thermica format :

Date : absolute in Julian day (vs 1950 or 2000) or simulation time

Frames : γ50, J2000, Sun/North oriented, launch site based (ex: Kourou)

Position : cartesian p(x,y,z) v(x,y,z) or keplerian (a, e, i, Ω, ω, M)

Orientation : euler angles (all conventions), rotation matrix, quaternions

(other needs will be considered if any)

After translation, verification byanimated display can be done

Launcher orbit 2D plot

Launcher orbit 2D plot

Launcher orbit 3D plotLauncher orbit 3D plot


RadiationREF & Fluxes computation

Monte Carlo Ray-tracing

Takes into account

Analytical shapes

Multi-reflection

Specular & diffusive Reflection and Refraction

Angle-dependent properties can be used

Automatic accuracy control

Statistical convergence is checked

The user can define the desired accuracy : automatic nb rays is computed

Incident angle dependent thermo-optical properties

Incident angle dependent thermo-optical properties

Ray tracingRay tracingSolar & planet fluxeson satellite in orbit

Solar & planet fluxeson satellite in orbit

Accuracy computed<

Accuracy specified

Accuracy computed>

Accuracy specified


RadiationPlanet IR and Albedo fluxes

Planet IR & Albedo can belatitude / longitude / time dependant

Extension of the projection algorithm

For each orbital position, the planet has a

non-uniform IR level & Albedo factor

The global flux level is integrated from all solid angles around the

spacecraft

Time dependant Earth temperatureprofile for IR flux computation

Time dependant Earth temperatureprofile for IR flux computation Solar flux on Earth for

Albedo flux computation

Solar flux on Earth forAlbedo flux computation


RadiationDisplay of rays

A useful post-processing display

Thanks to the display of rays, the user can visualize the Monte-Carlo

process in order to understand its behavior and to eventually add

corrections to the model or to the radiation options

1.000 rays from source1.000 rays from source10.000 rays from source10.000 rays from source


Radiation (available 2006) Solar flux

The Sun can now be a Sphere at a finite distance

A growing need coming from recent & future scientific missions

(Venus Express, Bepi Colombo, Solar Orbiter)

Ray Tracing + numerical integration to take

into account all geometrical and physical data

Numerical Integrationof finite Sun atFinite distance

Numerical Integrationof finite Sun atFinite distance

FiniteSun

n

Ssat

sat

Mi

S ,j

j D

sun

k

k

RsunO

InfiniteSun

Infinite Sun: No shadow transitionInfinite Sun: No shadow transition

Finite Sun: Shadow transitionFinite Sun: Shadow transition


Radiation (available 2006) Memory Limitations

The new release of the radiative module: “ No Limits” !Thanks to a new memory management, the radiation module can now handle:

Up to 30 000 and even more

New accuracy controlTo be compatible with the new unlimited version, the accuracy control has been updated:

A new simplified algorithm fast and easy to use

Up to thousands time steps

Solar Flux on detailed model (8000 nodes)

Solar Flux on detailed model (8000 nodes)


ConductionA Finite Element approach

New Finite Elements approach

Requirements

Geometry structured like a FEM (coincident and unique numbering)

Curved shapes with 180° maximum

Creation of the Edge Nodes (easy management by the user)

Mathematical background

Application of Fourier’s Law

Analytical Integration for curved shapes

Nodes structurefor conduction

Nodes structurefor conduction

kkk NTleQ .... ∇∇∇∇−−−−==== λλλλT1

iG12

N1

G13 G23

N2

N3

T3

T2

R1

R2

r z

h

r1 r2

rθ Rϕ

R



Results

Gives accurate results even with high distortion

Can output parameterized results (thickness and conductivity)(Useful for parametric or stochastic analysis at Solver level)

$CONSTANT$REALCONDUCTIVITY_ALU2024 = 1.20e+02;THICKNESS_ALU2024 = 1.00e-03;K1000 = CONDUCTIVITY_ALU2024;THICK1000 = THICKNESS_ALU2024;$CONDUCTORSGL(EDGE:2,1000) = K1000 * THICK1000 * 2.0E+00;

MeshingMeshing Temperatures profile Temperatures profile

Boundary conditions



Results

Gives accurate results even with high distortion

Can output parameterized results (thickness and conductivity)(Useful for parametric or stochastic analysis at Solver level)

$CONSTANT$REALCONDUCTIVITY_ALU2024 = 1.20e+02;THICKNESS_ALU2024 = 1.00e-03;K1000 = CONDUCTIVITY_ALU2024;THICK1000 = THICKNESS_ALU2024;$CONDUCTORSGL(EDGE:2,1000) = K1000 * THICK1000 * 2.0E+00;

MeshingMeshing Temperatures profile Temperatures profile

Boundary conditions

Temperatures profile Temperatures profile


ThermiSol: temperature solverClassical routines

Steady-state studies:

Iterative Newton-Raphson algorithm

Transient studies:

Crank-Nicholson algorithm

Those have been intensivelyvalidated and used on real projects

(MEX, Pleiades, Ariane5, Arabsat,

VEX, Melfi, Intelsat10, Inmarsat4,

HotBird8, Metop, Amazonas, Anik,

W3A, ISS, Gaia, LHP…)

Temperature integration on spacecraftTemperature integration on spacecraft


ThermiSol: temperature solverInnovating routines

Innovating routines

Automatic time-stepping

According to a range of error allowed by the user, the time-steps automatically increase or decrease. The error is estimated by the third order of the Taylor development. This behavior assumes that the error is controlled and the time-steps optimized.

Parallel time-stepping

Also based on the error estimation, families of nodes are automatically and dynamically created. Each family has its own time scale. The computation is then a mix of the different time-steps. It provides much faster solution on models with different time scales.

Automatic time-steppingAutomatic time-stepping

Parallel time-steppingParallel time-stepping


Temperature Mapping (available 2006) By FEM analysis

An interface to the mechanical analysis

Easy to use. It requires:

The thermal geometry (SYSEXP file)

The temperature results (NTP file)

The mechanical mesh (BLK file native Bulk Nastran format)

Uses the same techniques than the new conduction module

Implies that the same requirements are needed

Curved shapes are managed analytically

Exact on purely conductive models

Thanks to the accurate finite elements method

Semi-automatic mapping

Possibility to define groups and families of nodes in order to define

manual associations


Temperature Mapping (available 2006) By FEM analysis

Associations definitionAssociations definition

THERMICA geometryTHERMICA geometryNASTRAN geometryNASTRAN geometry


Temperature Mapping (available 2006) Validation on standard shapes

Exact onLinear

Solution

Temperature profile computedon thermal meshes

Temperature profile computedon thermal meshes Temperature profile mapped

on mechanical meshes

Temperature profile mappedon mechanical meshes

Validatedon complexStructures


Temperature Mapping (available 2006) Validation on curved shapes

Parabola

Cone

Cylinder

Sphere





Curved shapes Curved shapes are analyticallyare analytically

integratedintegrated


Post-processing (available 2006) New solver output file

Thermica needs a more complete post-processing toolbox with new capabilities, including standard analysis and many others, an interface with standard software and also new 2D and 3D visualizations

Before creating a new post-processing environment, the choice of a

reference format and a method to store the data must be done. The new

output file of ThermiSol must be:

Binary: in order to minimize the cost of the storage

Multiplatform: to be post-process by any program, from anywhere

Well organized: to contain all the data of the run with fast access

Easy to manage: so anyone can create post-processing tools based

on this file

Flexible: a nodal filtering and frequencies of storage should

be specified by the user if necessary


Post-processing (available 2006) POSTHER : summary

Summary of the Thermica post-processing approach

Clean data storage in HDF5 format

Post-processing analysis operations

Link to external applications

Link to user own programs

TMM HDF5 file

POSTHER library

THERMICASOLVER

POSTHERanalysisprogram

THERMICAradiation

conduction…

POSTHERanalysisfiles

HDF5 compatible applications

CC++

User own programsFortran


Post-processing (available 2006) POSTHER: HDF5 format

“ Posther” Library : storage of temperature results

It is a library that uses the HDF5 format

in order to create a new kind of storage

that will replace the existing NTP file.

Advantage of HDF5 format :

Worldwide standard heavily used in scientific & industrial applications

Multi-platform binary format like jpg, pdf, … (Unix/Windows compatible)

Compatible with a lot of classical software (HDFexplorer, Matlab, …)

Content of the HDF5 file produced by Posther :

Information about the run + information about the model

Optional : Couplings (GL, GR, GF), Nodes properties (A, ALP, EPS, C),

Results (T, QS, QA, QE, QI, QR)

TMM HDF5 file

POSTHER library

THERMICASOLVER


Post-processing (available 2006) POSTHER: New solver output file

Storage options : a flexible approach

Nodal Filtering

A filter can be applied to store data only for some specified nodes

example: NODES=‘ #100, 120, SUB1: 100- 150, SUB2’

means that nodes 100 and 120 from the main model, nodes 100 to 150 from

model named SUB1 and nodes from model SUB2 will be stored in the file.

Storage frequencies

The data can either be stored at:

• The Initial Time

• A Low Frequency

• A High Frequency (for the most important data)

The frequencies allow the user to specify the number of time steps

or the time between each storage

example: temperature at each time step, GRs each 5 time steps


Post-processing (available 2006) POSTHER: New solver output file

Organization of theHDF5 file

Example of a .h5 file content

Example of a .h5 file content


Post-processing (available 2006) Analysis operations of the HDF5 file

Posther is also a post-processing analysis program

It gathers different utilities that can be launched at once, controlled by

an input parameter file

Information: gives basic information about the file and its content

NTP conversion: keeps the compatibility with tools based on NTP

CSV conversion: simple interface to Excel

Basic tools: like min/max studies, creation of “$INITIAL” paragraphs…

Posther gives also an API for user in-house programs

Contains Fortran and C routines to easily read the .h5 files so the user

will be able to create its own functions, modules or tools just by linking

with the Posther library.

Extended toolbox

Posther will soon become a toolbox with a complete library of analysis. It

will also include 2D and 3D visualizations.


Conclusion

Thermica is a complete thermal analysis software which includes:

Import of CAD (STEP) or FEM (BULK) geometries

Creation of a thermal geometry with all the material properties

Creation or import any orbit and kinematics + moving bodies

Advanced REF & fluxes with automatic accuracy control

Computation of conductive couplings by FEM approach

Computation of temperatures

Post-processing of results

Mapping of temperatures to mechanical meshes

The future V.4 will bring a new environment. It will gather all those capabilities and even more in a powerful friendly user software.

We have more ideas for the future and will also welcome yours !

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