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Feasibility and preliminary phases of space projects are aimed to answer to the very fundamental question whether a spacecraft (S/C) exists that can fulfil the mission objectives. In particular the thermal engineers must assess whether a possible configuration is feasible from the thermal point of view, or what modifications could make it suitable. The paper presents the Thermal Concept Design Tool (TCDT), a new software tool under development at Blue Engineering and Alenia Spazio for the European Space Agency (ESA), designed with the objective to assist the thermal engineers in reducing at minimum the effort required by simulation activities and focusing mainly on conceptual activities during feasibility and preliminary studies.

Stochastic method is being used in several domains for design optimisation, but its application to spacecraft thermal control design is not yet consolidated. The paper presents an assessment of this technique applied to spacecraft thermal control design, made by Blue Engineering and Alenia Spazio under ESA contract, with the objective to assess the applicability of the method, the requirements for its implementation, the effects on the design process.

The calculation of linear conductors for a thermal lumped parameter (TLP) model, to be used with ESATAN (ref 1.) or SINDA, is one of the last parts of the thermal model preparation that is not yet fully automated. Most users calculate the conductors by hand or have their own special spreadsheets, or other tools, which can calculate some of these for a series of combinations of simple shaped TLP-nodes. For TLP-nodes with more complex shapes these tools cannot be used. The current paper presents two generally applicable methods to automate the generation of the linear conductors for thermal lumped parameter models

EcosimPro is the European Space Agency (ESA) standard tool to support Environmental Control and Life Support Systems (ECLSS or ECLS) analysis. Processes used in ECLSS are multiple: fluid flow, heat transfer, chemical reactions, electro-chemical, biological, etc. As a result, EcosimPro is designed as a multi-disciplinary and flexible tool that can be easily adapted to simulate very different kinds of processes and systems. There is a standard library of EcosimPro, which is mainly adapted to model air loops of conventional ECLSS. Some extensions to this library have been implemented to perform detailed fluid flow analysis which are beyond the scope of the traditional fluid flow solvers available in Thermal Analysis software. The standard ECLSS library is well adapted to the thermo-hydraulic analysis of air cabin loops, but CELSS (Controlled Ecological Life Support System) and ATCS (Active Thermal Control System) have also been modeled by developing specific libraries of components.

Nowadays there are many well-proved and widely used software packages for the analysis of thermal and ECLS systems for space applications. These packages tend to be difficult to work with when they have to deal with aspects related to other disciplines. It may be rather cumbersome for example to couple at run time an ECLS package and a thermal package that have to exchange variables such as interface temperatures and heat flows or to re-use thermal models in real-time spacecraft simulators to support training and operations tasks. DC (including protocols and client/server libraries) addresses the widely discussed issue of creating multi- disciplinary and distributed applications, but focusing on the special requirements of Thermal and ECLS analysis tools used by ESA and by the European Space Industry.

EcosimPro is a multi-disciplinary simulation tool with a powerful object-oriented simulation language, state of the art solvers and a user-friendly environment with the look and feel of Microsoft® Visual Studio. It is the recommended ESA simulation tool for ECLS and has been used successfully for the European activities of the International Space Station program. Given its potential to address any kind of simulation, EcosimPro is increasingly being used at ESA and in Industry to carry out thermal and thermo-hydraulic simulations. This paper describes how EcosimPro can be used in this context and provides recent application examples.

This paper describes two possible modelling approaches (ESATAN and ESATAN/FHTS) for the thermo-hydraulic simulation of capillary driven fluid loops. The respective advantages and disadvantages of the approaches are discussed and are illustrated by an Industrial application, the development of a Deployable Radiator by the European consortium Astrium.

ESA and EMPRESARIOS AGRUPADOS have been developing EcosimPro since 1989. The initial objective was to provide powerful capabilities to handle the simulation of Environmental Control and Life Support Systems (ECLSS). Because of the multi-disciplinary nature of ECLSS (thermal, fluids, chemical reactions, electrical and control features), EcosimPro has been designed as a generic, flexible and modular tool. It is capable of solving a large set of Differential Algebraic Equations (DAEs) both for steady and transient states. The new EcosimPro 3.0 release (available on PC-Windows platform) uses the powerful concept of Object-Oriented Simulation Language, which enables the definition of components that can be re-used as libraries. The look and feel of EcosimPro is identical to Microsoft® software (tree browser for instance) and is very user-friendly.

Numerous workers have made effort to harness the flexibility of spreadsheets to analyse thermal problems. One approach has been to execute a thermal analysis within the spreadsheet itself, however the usefulness is limited by the performance of the built-in solvers. In addition, spreadsheets must either be custom built for each application or founded on parameterised models from similar analyses. An alternate approach has been to add spreadsheet like capability to existing tools. Again, this loses the full flexibility of a spreadsheet. To overcome these limitations, ThermXL has been developed. ThermXL is a thermal lumped parameter network solver and generic model builder that is fully integrated within Microsoft® Excel. It is very flexible easy-to-use tool that is particularly suited to preliminary design and “What if…?” type parametric analyses. This paper describes the utility, functionality and architecture of ThermXL.