ON SE PROPOSE D'ETUDIER LES TRANSFERTS DE CHALEUR COUPLES INTERVENANT DANS LES FOURS HIP FONCTIONNANT A TRES HAUTE PRESSION ET HAUTE TEMPERATURE. L'ETUDE PORTE PLUS PARTICULIEREMENT SUR LA CARACTERISATION, DANS CES CONDITIONS EXTREMES, DES PROPRIETES DU FLUIDE DE TRAVAIL (L'ARGON) ET DE L'ISOLANT FIBREUX (FEUTRE DE CARBONE) CONSTITUANT LE CALORIFUGEAGE DE L'ENCEINTE HAUTE TEMPERATURE. L'ETUDE S'EST ATTACHEE A CARACTERISER LES PROPRIETES THERMOPHYSIQUES DU FLUIDE DE PRESSION (GAZ ARGON) A HAUTE TEMPERATURE ET A HAUTE PRESSION. DES MESURES DE CONDUCTIVITE THERMIQUE PAR UNE METHODE A FIL CHAUD EN REGIME TRANSITOIRE SONT PROPOSEES. L'ETUDE DE LA MORPHOLOGIE DU FEUTRE DE CARBONE EST COMPLETEE PAR LA DETERMINATION DU COEFFICIENT D'EXTINCTION PAR UNE VOIE EXPERIMENTALE (MESURE DE TRANSMITTIVITE) ET PAR DES CALCULS (THEORIE DE LA DIFFUSION DE MIE). DES MESURES DE LA CONDUCTIVITE THERMIQUE EFFECTIVE DU FEUTRE DE CARBONE DANS UN INTERVALLE DE TEMPERATURE COMPRIS ENTRE QUATRE CENTS ET HUIT CENTS KELVIN POUR DES PRESSIONS COMPRISES ENTRE UN MILLIBAR ET DEUX MILLE BARS SONT PRESENTEES. UN MODELE DE CONDUCTION DANS LA MATRICE FIBREUSE EST PROPOSE. LE MODELE PREND EN CONSIDERATION LES PHENOMENES DE CONSTRICTION ET DE RESISTANCE DE CONTACT ENTRE FIBRES DE MANIERE GLOBALE. UN PARAMETRE DE COUPLAGE PERMET D'ESTIMER L'IMPORTANCE DE CES PHENOMENES EN FONCTION DE LA PRESSION DE GAZ INTERSTITIEL

The first crisis in energy prices was undoubtedly a strong stimulus for the involvement of the Commission of the European Communities in research and development on alternative energy sources. Indeed, the need to overcome difficulties faced by the Community as a whole, particularly those resulting from its severely unbalanced energy supply, made a common Community approach seem especially apt. This reasoning also applies to energy R&D, bearing in mind that responses to the crisis should be not only political or economic, but also scientific. Four years have passed since the decision of the Council of Ministers to launch the first Community Energy Research and Development Programme, dealing with geothermal energy, solar energy, hydrogen production and utili sation, energy conservation and energy systems analysis. A seminar on geo thermal energy was held two years ago to report on work in progress at the half-way stage of the four-year programme. The second international seminar, reported in this volume, was arrang ed so as to provide an opportunity to examine the final outcome of this Community investment in research in geothermal energy. This proceedings volume therefore has two main aims: - to present an evaluation of the results of the Community geothermal programme, by means of 83 formal reports describing the individual research programmes; - to show how the Community research programme fits into the overall context of national and international research on geothermal energy, by including the presentations of six guest speakers who introduced the sessions and gave keynote addresses.

Vols. 6- include supplementary material of Publications, Reports, Work, etc. of the Institute and some of its commissions.