Center for thermophysical data of the ministry of atomic energy of the Russian federation

Abstract

The Center for Thermophysical Data (CTD) [1] was founded in 1980. In 1986, at the decision of Soviet State Committee on Atomic Energy, it was raised to the status of an industry center, and as such it is a unit of the industry system of standard reference data.The main task of the Center is to provide scientific and design studies of reliable information about the thermohydraulics of nuclear power plants. To fulfil this mission, a technology of preparation, processing, and analysis of information, making it possible, in interaction with qualified specialists (experts) at the Thermophysical Division of the Physics and Power Engineering Institute (PPEI) and other enterprises, to prepare for dissemination of very accurate and reliable information, has been created at the Center. Aside from the content of the information base, experience in developing and adopting the information technology accumulated at CTD is certainly of interest and may be helpful for other fields of knowledge.Technology of Information Accumulation. The main principles adopted for the construction of an information technology are as follows:directed at all users who are included in scientific and design work for nuclear power plants; possibility of tracing the type of information (experimental, estimated, recommended), origin and history of any unit of storage (author, accompanying information); oriented toward different computer platforms. The technology includes: acquisition of experimental data on thermohydraulic processes in different power equipment followed by construction of an archive, thematic compilations, and databanks; assessment and analysis of experimental data for generating reliable and comprehensive, well-grounded, working recommendations; expert assessment of the reliability of recommendations and their computational testing; preparation and publication of periodic collections of recommendations (RTM); development of specialized databanks and more complicated program products, such as knowledge bases based on recommended information.Archive of Experimental Data. The experimental data from thermophysical investigations enter an archive [2, 3], and they are tested by different methods and archived in accordance with a thematic heading, which is the basis of search operations. The archive consists of a structured collection of text files and all archiving operations are performed under the control of a specially developed system of programs. The source of information on the contents of the archive are useraccessible catalogs, including KATED database (MS-DOS, personal computers).At present, the archive contains data on the following subjects: crisis of heat emission during flow of water in circular, rectangular, and triangular pipes, ring channels and rod bundles; true volume steam content in pipes, ring channels, rectangular slits, and rod bundles; pressure drop in two-phase flow for rod bundles; hydraulic resistances in one-phase flows for rod bundles; heat transfer to water, gases, and liquid metals for rod bundles;

Numerical and Experimental Analysis of Dual-Beam Laser Polishing Additive Manufacturing Ti6Al4V

“…The temperature dependence of dynamic viscosity, specific heat, density, and thermal conductivity was considered, as shown in Figure 8 [ 17 , 27 , 28 ]. Other property parameters of Ti6Al4V are listed in Table 3 [ 20 , 21 , 22 , 27 , 29 ].…”

“…In this model, the CW laser with top-hat energy distribution is applied to the material surface, and then the pulse laser with a Gaussian energy distribution is applied to the material surface after cooling for 500 ms. Therefore, the heat flux on boundary 2 is written as [ 29 ]: where is the CW laser heat source, is the CW laser power, is the CW laser spot, is the position of the CW laser, is the beginning position of the CW laser, and and are the velocity and time of the CW laser, respectively. Similarly, is the pulse laser heat source with a Gaussian distribution, is the pulse laser power, is the radius of the pulse laser, and is the velocity of the pulse laser.…”

“…In this model, the CW laser with top-hat energy distribution is applied to the material surface, and then the pulse laser with a Gaussian energy distribution is applied to the material surface after cooling for 500 ms. Therefore, the heat flux on boundary 2 is written as [29]:…”

Simulação com programas computacionais de desempenho do combustível em regimes permanente e transiente de varetas combustíveis de aço inoxidável austenítico

“…Os aços austeníticos são considerados como isotrópicos em relação às Os aços estabilizados de baixo carbono da série 300, apresentam uma expansão térmica média de 16,6 µm/(m-K); na faixa térmica de 20 °C a 100 °C, a função é crescente com a temperatura. Essa relação é a média dos seguintes aços 321, 347, 348[69]. Se houver a expansão da faixa de temperatura de 20 °C a 600 Zircaloy, os códigos de desempenho utilizam a correlação de Mehan-Wiesinger proposta, em 1961, para temperaturas abaixo de 799,85 ºC.…”