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    This library is written in Modelica. The purpose of this library is to calculate fluid properties from an equation of state (EoS), directly within Modelica and not from an external dll. It supports EoS of the form f=f(T,d) meaning Helmholtz energy as a funtion of temperature and density. In addition to all state properties, this library calculates viscosity, thermal conductivity and surface tension. So far, the fluids n-Butane, R134a and Isobutane are implemented, but not fully validated. The next fluids to be implemented are probably isopentane, propane, ammonia, CO2 and other possible working fluids for Organic-Rankine-Cycles.
    12 years ago by @thorade
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    Mission The Thermophysical Properties Division provides the best available measurements, theory, computations, and data evaluation for the thermophysical property information required to enable development of standards, enhance productivity, facilitate trade, ensure scientific and technological progress, and improve the quality of life. Overview The Thermophysical Properties Division (TPD) was formed at the beginning of 2008 by a reorganization which separated the old Physical and Chemical Properties Division into two entities with distinct focuses and each housed on one of the two main campuses of NIST. The TPD is a Division of the Material Measurement Laboratory located on the Boulder campus. The Thermophysical Properties Division strives to be the foremost and best source of high quality thermophysical property information. This vision is driven by the ubiquitous importance of this information to commerce, industry, manufacturing, and national policy objectives. The Division meets its challenges through an integrated program of experimental measurement, data collection and evaluation, development of theoretically based models, and simulation of model systems. Among the outputs of the Division are computerized standard reference databases which synthesize thermophysical property information in forms which are conveniently used by our stakeholders. The vast majority of commodity exchanges in chemicals, energy related fluids, and materials are based on physical and chemical properties. In some cases, national and international standards for these properties are needed, such as the AGA-8 equation of state for the properties of natural gas, ASME-IAPWS Properties of Water and Steam, ISO-Standard Equations for refrigerants. Generally these standards are presented in the form of high accuracy equations of state which allow determination of a wide range of thermodynamic properties. Additionally, performance criteria of working fluids, feedstock, chemicals, and cryogenic systems are inextricably linked to thermophysical properties, e.g. density, viscosity, boiling point, phase behavior, heat capacity, stability, etc. Engineering design, optimal operation, and innovation for engines, chemical manufacturing, power generation, heating and air conditioning, distillation, etc. depends critically on knowledge of these properties. Reliable properties data are critical to competitive advantage, sustainability, and innovation. Finally, we note that widespread reliance of industry on properties information, success in setting and achieving national energy, environmental, and security goals often requires an extensive and trustworthy properties information-base. To meet the broad spectrum of needs, only briefly sketched above, the Division’s work is structured along four synergistic themes: * Develop and maintain the measurement capabilities, standard materials and reference data needed to underpin a national system of thermophysical property measurements; * Develop large-scale, readily accessible data resources providing trustworthy property information meeting high priority needs for a broad range of industries and national agendas; * Develop empirical and fundamental predictive capabilities to enable reliable estimation of property values when experimental data are unavailable; Research experimental techniques and address key data-gaps in support of specific, high priority industrial and national initiatives. These themes allow effective response to customer needs and are consistent with the Division’s operating strategy to maintain a highly synergistic research program that includes an appropriate balance of measurement, theory, and predictive models. The combination of the Division’s world class expertise and unrivaled resources in measurement, archiving, and provision of high-quality property data is complemented by its forefront research to develop reliable and highly adaptable methods for estimating property data in cases where measurements are unavailable or extremely difficult and/or costly to obtain. Core Expertise The expertise in the Division is broadly distributed within the fields of thermophysical properties and processes, emphasizing (1) data infrastructure and access; (2) predictive theory and models; and (3) experimental tools and measurements. More specifically, the Division maintains competence in data evaluation and dissemination; property models for industrial use; measurement of thermophysical properties; cryogenic technologies; separation technologies; fuel properties; and properties for environmental chemistry. Key Interactions with Customers Division outputs are routinely used in a variety of industrial, governmental, and academic settings. For instance, through a collaboration with Aspen Technology, evaluated data from the NIST Thermodynamic Data Engine are available to some 60,000 chemical plants world-wide. A consortium of chemical and related companies provides direct input to the data collection and evaluation programs of the Thermodynamic Research Center Group. The NIST REFPROP database was purchased by some 1200 customers in 2008, and all cryogenic flow meters in the U.S. are tied to the Division’s calibration and testing services. The Division houses the editorial offices of the International Journal of Thermophysics (and provides an editor of the Journal of Physical and Chemical Reference Data) and organizes the triennial Symposium on Thermophysical Properties to maintain connections. Sponsored research in the Division also provides direct links to key customers: work with DOD (primarily the Air Force) is important to our fuels program; DHS funds some of our work on properties and data for explosives; DARPA works with the Division in its micro-cryocooler project; DOE is engaged in our properties work related to advanced power generation and in gas hydrates data. Future Directions and Plans The National challenges related to energy security and monitoring/mitigating anthropogenic climate (or other environmental) changes are reflected in the Division’s plans. The Division recently held workshops on property needs for biofuels and aerospace fuels: alternative fuels and feedstocks will command an increased emphasis in the future.
    14 years ago by @thorade
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    Entsprechend der Mission der Helmholtz-Gemeinschaft, Beiträge zur Lösung großer und drängender Fragen von Gesellschaft, Wissenschaft und Wirtschaft zu leisten, hat das Thema Open Access eine signifikante Bedeutung für die Helmholtz-Zentren. Der freie Zugang zu wissenschaftlichen Erkenntnissen fördert Leistungsfähigkeit und Innovation: Open Access verbessert die Informationsversorgung der Wissenschaft weltweit, erleichtert den Transfer von Forschungsergebnissen in die Wirtschaft und ermöglicht der Gesellschaft den einfachen Zugang zu Wissen und Information. Die Helmholtz-Gemeinschaft gehörte 2003 zu den Erstunterzeichnern der "Berliner Erklärung". Diese Position wurde durch die Mitgliederversammlung ausdrücklich bestätigt: „Publikationen aus der Helmholtz-Gemeinschaft sollen künftig ohne Ausnahme kostenlos zugänglich sein, soweit nicht ausdrückliche Vereinbarungen mit Verlagen und anderen dem entgegenstehen.“ (Beschluss der Mitgliederversammlung vom 27.09.2004) Wissenschaftlerinnen und Wissenschaftler der Helmholtz-Gemeinschaft sind als Herausgeberinnen und Herausgeber von Open-Access-Zeitschriften aktiv und speichern Ihre Arbeiten in Repositorien (frei zugänglichen Online- Volltextdatenbanken), die von Bibliotheken- und Rechenzentren betrieben werden. Seit 2005 unterstützt das Helmholtz Open Access Projekt die Zentren bei der Umsetzung von Open Access. Einen Schwerpunkt der Aktivitäten nimmt das Themenfeld Forschungsdaten ein. Helmholtz-Zentren stellen sich der Herausforderung des zeitgemäßen Umgangs mit Forschungsdaten unter Berücksichtigung der Nachnutzung und der langfristigen Erhaltung.
    14 years ago by @thorade
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publications  43