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commit bd6ea68bc0f768973214e56c109f4cffa536a99b
parent 3c8bdcde6a5e81a4005965d6ab2b68854cb481d1
Author: Christophe Coustet <christophe.coustet@meso-star.com>
Date:   Wed, 29 Nov 2017 17:28:52 +0100

A pass on English

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1 file changed, 82 insertions(+), 83 deletions(-)

diff --git a/stardis.html.in b/stardis.html.in @@ -2,39 +2,37 @@ <h1>Stardis - The Monte-Carlo solver for coupled thermal problems</h1> </header> -<p>Stardis computes the <b>propagator</b> or the <b>Green function</b> of -coupled thermal problems under the linear assumption. <b>Coupled</b> refers to -conductive, convective and radiative transfers . Stardis can deal with complex -geometries and complex high-frequency external solicitations compared to the -characteristic time of the system.</p> - -<p>Stardis does not compute the whole field of temperature. It computes a -specific observable such as a temperature at a probe point or the mean -temperature in a specific volume. And more than the temperature value, -Stardis gives an evaluation of the propagator. The knowledge of the propagator -is useful for thermal engineer because it gives some crucial informations to -analyse the heat transfer in the system. The engineer accesses at some new -informations like <b> "from where the heat comes at this location ?"</b>. -Among the possibilies given by the propagator, it can be used as a rapid modele -without simplifying the geometrical description. </p> - -<p>The algorithms implemented in Stardis are inherited from the state of the -art of the Monte-Carlo method applied to radiative transfers physics (Delatorre -[1]) combined to the statistical point of view of the conductive heat transfer -(Kac [2] and Muller [3]). And this theoritical framework can be used in pratice -to deal with the complex geometries thanks to the state of the art of computer -graphics which it's at the origin of a disruptive technology in the cinema -industry (FX and animated movies).</p> - -<p> This theoritical framework leads to a <b>statistical point of view</b> of -the whole heat transfer processess (conductive-convective-radiative) when the -linear assumption is relevant. And this modele can be solved by a -<b>Monte-Carlo approach</b> which samples some <b>thermal paths</b>. This type -of algorithms can be considered as an extension of Monte-Carlo algorithms to -solve radiative transfer by sampling optical paths. An interesting property of -this approach is that the resulting algorithms does not rely on a volume mesh -of the system. </p> - +<p>Stardis computes the <b>propagator</b> (aka the <b>Green function</b>) of +coupled thermal systems under the linear assumption. Here <b>coupled</b> +refers to conductive, convective and radiative transfers. Stardis can deal +with complex geometries as well as high-frequency external solicitations +over very long period of time, relative to the characteristic time of the +system.</p> + +<p>Stardis does not compute temperature fields as a whole. It is designed to +compute specific observables such as temperatures at probe points / dates or +the mean temperature in a specific volume / period of time. In addition to +temperature values, Stardis gives access to an evaluation of the propagator. +The propagator is of great value for thermicist engineers as it gives some +crucial information to analyse heat transfers in the system. It helps engineers +answer questions like <b>"Where from does the heat come at this location?"</b>. +Propagators seamlessly agregate all the provided geometrical and physical +information on the system in an unbiased and very-fast statistical model.</p> + +<p>Stardis' algorithms are based on state-of-the-art Monte-Carlo method applied +to radiative transfer physics (Delatorre [1]) combined with conduction's +statistical formulation (Kac [2] and Muller [3]). Thanks to recent advances in +computer graphics technology which has already been a game changer in the +cinema industry (FX and animated movies), this theoritical framework can now +be practically used on the most geometrically complex models.</p> + +<p>Everytime the linear assumption is relevant, this theoritical framework +allows to encompass all the heat transfer mecanisms (conductive-convective- +radiative) in an <b>unified statistical model</b>. Such models can be solved by +a <b>Monte-Carlo approach</b> just by sampling <b>thermal paths</b>. This can +be seen as an extension of Monte-Carlo algorithms that solve radiative transfer +by sampling optical paths. A main property of this approach is that the +resulting algorithms does not rely on a volume mesh of the system.</p> <h2>An example of propagator use</h2> @@ -47,17 +45,18 @@ device): defined by the bottom face tempature, and the environment temperature (exchange by convection), <li> the value of interest is the core temperature (semiconductor junction) - in the red-colored region of the IGBT which also the source of dissipated - power (see <i>The IGBT model</i> figure), + in the red-colored region of the IGBT which is also the source of dissipated + power (see figure below), <li> the propagator has been precomputed using the Stardis Monte-Carlo - solver from the 3D description of the model and the materials properties - (see <i>A visualization of the propagator</i> figure), + solver from the 3D description of the model and the materials' properties + (see figure below), <li> on request, the propagator is applied to the user-provided temperatures - and the dissipated power; it acts as a super-fast direct model to compute the - value of the core temperature, + and dissipated power; it acts as a super-fast direct model to compute the + value of the core temperature together with its statistical uncertainty + (standard error), <li> as it carries temporal information, the propagator could be used in - transient computations; in this case the two input temperatures would - be temporal data. + transient computations; in this case the input temperatures and dissipated + power would be temporal data. </ul> </p> @@ -67,11 +66,12 @@ device): <img src="IGBT.png" align="middle" alt="IGBT"> </a> <div class="caption"> - A simple IGBT example. The points represent the end of a "thermal path" - when it reaches a boundary condition. The colour of a point indicates the - time to reach this boundary. This example has been developped in - collaboration with <a href="https://www.epsilon-alcen.com" >Epsilon-Alcen - company </a>. + <b>A simple IGBT example.</b> Each point represents the end of a "thermal + path", where it reaches a boundary condition. The colour of the points + indicates the duration (in seconds) of the thermal path, that is the time + it tooks for heat to escape the system from the source. This example has + been developped in collaboration with + <a href="https://www.epsilon-alcen.com">Epsilon-Alcen</a>. </div> </div> @@ -96,24 +96,25 @@ Core temperature: <input type="text" id="T_res_std" value="---" readonly> </div> -<h2>Get Stardis</h2> +<h2>Getting Stardis</h2> -<p>Stardis is not a monolothic software, it's <b>a solver which can be +<p>Stardis is not a monolothic software, but <b>a solver which can be integrated</b> in various thermal engineering simulation toolchain for designing and optimizing.</p> -<p>To get Stardis, contact us, we have a versatile commercial offer:</p> +<p>If you want to get access to Stardis, please contact us. Our commercial +offers are versatile:</p> <ul> - <li> we can provide a Stardis SDK for developpers,</li> - <li> we can integrate Stardis in your software toolchain,</li> - <li> we can develop a custom software.</li> + <li> we can provide software developpers with a Stardis SDK,</li> + <li> we can integrate Stardis in any software toolchain,</li> + <li> we can develop custom software from / on top of Stardis.</li> </ul> -<p> Stardis is available under many licences. That depends on your status -(industry or academic) and development constraints (open-source, proprietary, -...). Of course, these offers can be accompanying with theoretical and practice -trainings.</p> - +<p>Depending on your status (industry or academic) and development constraints +(open or closed source, ...) Stardis can be made available under the adequate +license. Of course, both theoritical and software development training is +proposed on a regular basis as well as on demand to help you master all the +power of our innovative approach.</p> <h2>Examples of integration and development</h2> @@ -128,20 +129,18 @@ trainings.</p> </div> </div> -<p> For its needs of numerical simulations of thermal transfers, EDF R&D -develops and maintains since several years the SYRTHES software. It solves the -conductive and radiative transfers in complex geometries and it was designed to -be integrated in the EDF software toolchain (SALOME). The conductive heat -transfer is solved by finite elements method and the radiative solver is based -on radiosity method.</p> - -<p> Meso-Star and the SYRTHES developers collaborate since 2015 to integrate -new features in SYRTHES based the statistical point of view of the thermal -transfers. Meso-Star accompanies SYRTHES developers to integrate Stardis. The -objective is not replacing the existing solvers but rather than adding <b>some -complementary features to facilitate the analysis of numerical -simulations</b>.</p> +<p>Mainly to address its own numerical simulation needs on thermal transfer, +EDF R&D has been developing and maintaining the SYRTHES software for years. +SYRTHES is dedicated to solve the conductive and radiative transfers in +complex geometries and was designed to be integrated in the EDF software +toolchain (SALOME). Inside SYRTHES, the conductive heat transfer solver is a +finite elements solver and the radiative solver is based on radiosity.</p> +<p>Meso-Star staff and SYRTHES developers collaborate since 2015 to incorporate +new features into SYRTHES, based on Stardis and its statistical point of view +of the thermal transfers. The purpose is not to substitude new solvers to the +existing ones, but rather to add <b>some complementary features to help +analysing numerical simulations results</b>.</p> <h3> PROMES-CNRS - Star-Therm </h3> @@ -150,24 +149,24 @@ simulations</b>.</p> <img src="star-therm.png" style="float: relative" alt="Star-Therm"> </a> <div class="caption"> + Star_combined conductive–radiative heat transfer Star-Therm: A code to solve conducto-radiative thermal problems in complex foams. </div> </div> - -<p>Meso-Star has developped for the PROMES-CNRS laboratory the Star-Therm code -based on Stardis solver which solves coupled conducto-radiative thermal -problems. It was designed to deal with complex geometries such as <b>metallic -or SiC foams</b>. This type of foams are used as heat exchanger in solar -<b>concentrated solar process</b> to transfer energy from incoming sunlight -radiation to a working fluid.</p> - -<p>The physical model consists in taking into account coupled thermal radiation -in vacuum and conduction in opaque solids. Incoming solar energy (radiation) is -deposited at the surface of a metallic foam, which results in a given boundary -temperature. Therefore, boundary conditions and initial conditions are known. -Star-Therm will subsequently have to compute the temperature at any position +<p>Based on the Stardis solver which solves coupled conductive and radiative +thermal problems, Meso-Star has developped the Star-Therm code for the +PROMES-CNRS laboratory. Star-Therm is designed to deal with the geometric +complexity of <b>metallic or SiC foams</b>. This type of foam is used in the +design of heat exchangers in concentrated solar processes to transfer the +energy of the incoming sunlight radiation to a working fluid.</p> + +<p>The physical model in Star-Therm considers the incoming thermal radiation +in vacuum and its coupling with conduction in an opaque solid. The incoming +solar energy (radiation) is deposited at the surface of the metallic foam, +which allows to determine a boundary temperature. Knowing boundary conditions +and initial conditions, Star-Therm can compute the temperature at any position within the solid.</p> <h2>References</h2>