The DYNASIMUL Project - Summary
Etienne Wurtz, project coordinator

The DYNASIMUL project began in April 2006, at a time when there was little investment, in France, in the field of the dynamic simulation of buildings. Its primary objective was to bring together the various teams working in this area in order to obtain a critical mass of researchers. So a large number of laboratories - university, CNRS, Armines, CEA and CSTB - were brought in to discussions on the prospects of simulation, each team contributing according to its area of competence and its means.

We chose to investigate three distinct sections:

The first concerns the coupling of environments through dll-type objects in order to show that it is not necessary to work towards a single code of calculation for all users but that computer tools can enable the coupling; this has been demonstrated, notably, by coupling the MATLAB-SIMULINK and TRNSYS environments.
This first result also brought out the limits of this type of modelling and led us to develop our approach in the SIMENTHEC project, in which the coupling was affected by a platform acting as the interface between the different software programs; rather than having them code-simulate 2 by 2, this permitted the simultaneous use of several types of simulation tool.

The second consists of developing a library of models, DYNASIMUL, in order to conserve and make available a large number of models. Many models have been developed in thesis work only to disappear afterwards. An operational tool was thus needed to provide the documentation and references which would guarantee the quality of the models recorded in the databank and thus ensure the latter’s reproducibility. Such conservation is also being done outwith the DYNASIMUL project, in the CETHIL laboratory of the INSA, Lyon, thanks to support received for the project CLIMB, financed by the ministry of research; this will permit the continued development of the databank of models in a server at the INSA of Lyon.

The third section is that of a reflection on the development of modelling in different domains, in view of the specificity of the construction sector and its complex modelling and of the need to reduce models and to have robust solvers for non-linear equations. Various modelling approaches have been developed for the resolution of three-dimensional, dynamic flow, both aeraulic and, for long periods, at ground level. This reflection has led to the proposition to set up new projects (notably in ANR HABISOL) such as SUPERBAT, PLUMES and FIABILITE, which will allow the realisation of the propositions made so far in the DYNASIMUL framework, bearing in mind that a fairly large number of teams is now involved in activities involving the thermal modelling of buildings.

The DYNASIMUL undoubtedly represents a real turning-point in the field of simulation: it started with a dispersed and under-developed offer to proceed towards the offer of various software programs, brought together on a single platform and having an increasingly ambitious capacity to solve all types of energy problem in buildings.