@article{MTMT:34751458, title = {Energy-Dependent, Self-Adaptive Mesh h(p)-Refinement of a Constraint-Based Continuous Bubnov-Galerkin Isogeometric Analysis Spatial Discretization of the Multi-Group Neutron Diffusion Equation with Dual-Weighted Residual Error Measures}, url = {https://m2.mtmt.hu/api/publication/34751458}, author = {Wilson, S.G. and Eaton, M.D. and Kópházi, József}, doi = {10.1080/23324309.2024.2313460}, journal-iso = {J COMPUT THEOR TRANSP}, journal = {JOURNAL OF COMPUTATIONAL AND THEORETICAL TRANSPORT}, unique-id = {34751458}, issn = {2332-4309}, abstract = {Energy-dependent self-adaptive mesh refinement algorithms are developed for a continuous Bubnov-Galerkin spatial discretization of the multi-group neutron diffusion equation using NURBS-based isogeometric analysis (IGA). The spatially self-adaptive algorithms employ both mesh (h) and polynomial degree (p) refinement. Constraint-based equations are established across irregular interfaces with hanging-nodes; they are based upon master-slave relationships and the conservative interpolation between surface meshes. A similar Galerkin projection is employed in the conservative interpolation between volume meshes to evaluate group-to-group source terms over energy-dependent meshes; and to evaluate interpolation-based error measures. Enforcing continuity over an irregular mesh does introduce discretization errors. However, local mesh refinement allows for a better allocation of computational resources; and thus, more accuracy per degree of freedom. Two a posteriori interpolation-based error measures are proposed. The first heuristically minimizes local contributions to the discretization error, which becomes competitive for global quantities of interest (QoIs). However, for localized QoIs, over energy-dependent meshes, certain multi-group components may become under-resolved. The second employs duality arguments to minimize important error contributions, which consistently and reliably reduces the error in the QoI. © 2024 The Author(s). Published with license by Taylor & Francis Group, LLC.}, keywords = {Isogeometric analysis; constraint-based local refinement; continuous Bubnov-Galerkin; dual-weighted residual error measures; energy-dependent self-adaptive mesh h(p)-refinement; Multi-group neutron diffusion equation}, year = {2024}, eissn = {2332-4325} } @article{MTMT:34742501, title = {Enhancing higher education through hybrid and flipped learning: Experiences from the GRE@T-PIONEeR project}, url = {https://m2.mtmt.hu/api/publication/34742501}, author = {Demazière, C. and Stöhr, C. and Zhang, Y. and Cabellos, O. and Dulla, S. and Garcia-Herranz, N. and Miró, R. and Macian, R. and Szieberth, Máté and Lange, C. and Hursin, M. and Strola, S.}, doi = {10.1016/j.nucengdes.2024.113028}, journal-iso = {NUCL ENG DES}, journal = {NUCLEAR ENGINEERING AND DESIGN}, volume = {421}, unique-id = {34742501}, issn = {0029-5493}, abstract = {GRE@T-PIONEeR is a Horizon 2020 project coordinated by Chalmers University of Technology, running over the period 2020–2024. 18 university teachers from 8 different universities located in 6 different countries gathered forces to develop and offer advanced courses in computational and experimental nuclear reactor physics and safety. All courses are flipped hybrid courses, i.e., students work on online preparatory activities at their own pace before attending a set of interactive sessions organized on five consecutive days. Those sessions can be attended either onsite or remotely. During the academic year 2022/2023, 8 different courses were offered, and 185 students successfully completed the courses, with a success rate of 87.7% for the students taking at least one activity during the interactive sessions. Student behaviour and performance were monitored via the Learning Management System (LMS) used in all courses. This paper presents an analysis of various metrics from the LMS and demonstrates a high level of engagement of the students committed to the courses and a high success rate for those students. Whereas all students are equally engaged in the online preparatory work and perform equally well, significant differences exist during the interactive sessions between the students who opted for onsite participation and those who attended the sessions online, with the onsite students outperforming the online students. © 2024 The Authors}, keywords = {Learning systems; Students; Nuclear reactors; Education and training; Teaching; E-learning; Online learning; Online learning; Active learning; Active learning; Reactor physics; Flipped classroom; Flipped classroom; hybrid teaching; hybrid teaching; Computational reactor physics; Experimental reactor physics; Nuclear education and training; Computational reactor physic; Experimental reactor physic; Nuclear education; Nuclear training}, year = {2024}, eissn = {1872-759X}, orcid-numbers = {Szieberth, Máté/0000-0001-9192-0352} } @article{MTMT:34738091, title = {Relativisztikusan mozgó állóhullám}, url = {https://m2.mtmt.hu/api/publication/34738091}, author = {Sükösd, Csaba and Bokor, Nándor}, journal-iso = {FIZIKAI SZEMLE}, journal = {FIZIKAI SZEMLE}, volume = {74}, unique-id = {34738091}, issn = {0015-3257}, year = {2024}, pages = {66-70} } @article{MTMT:34735228, title = {Discussion and perspectives for improvements of heat transfer correlation capabilities for fluids at supercritical pressures}, url = {https://m2.mtmt.hu/api/publication/34735228}, author = {Varju, Tamás and Csige, András and Kiss, Attila and Filonov, V. and Filonova, Y. and Fedorov, D. and Pucciarelli, A. and Kassem, S. and Ambrosini, W.}, doi = {10.1016/j.nucengdes.2024.113085}, journal-iso = {NUCL ENG DES}, journal = {NUCLEAR ENGINEERING AND DESIGN}, volume = {421}, unique-id = {34735228}, issn = {0029-5493}, year = {2024}, eissn = {1872-759X}, orcid-numbers = {Varju, Tamás/0000-0002-2969-1867; Kiss, Attila/0000-0002-8600-2300} } @article{MTMT:34733895, title = {Fractals and Chaos in the Hemodynamics of Intracranial Aneurysms}, url = {https://m2.mtmt.hu/api/publication/34733895}, author = {Závodszky, Gábor and Gyürki, Dániel László and Károlyi, György and Szikora, István and Paál, György}, doi = {10.1007/978-3-031-47606-8_20}, journal-iso = {ADVANCES IN NEUROBIOLOGY}, journal = {ADVANCES IN NEUROBIOLOGY}, volume = {36}, unique-id = {34733895}, issn = {2190-5215}, abstract = {Computing the emerging flow in blood vessel sections by means of computational fluid dynamics is an often applied practice in hemodynamics research. One particular area for such investigations is related to the cerebral aneurysms, since their formation, pathogenesis, and the risk of a potential rupture may be flow-related. We present a study on the behavior of small advected particles in cerebral vessel sections in the presence of aneurysmal malformations. These malformations cause strong flow disturbances driving the system toward chaotic behavior. Within these flows, the particle trajectories can form a fractal structure, the properties of which are measurable by quantitative techniques. The measurable quantities are well established chaotic properties, such as the Lyapunov exponent, escape rate, and information dimension. Based on these findings, we propose that chaotic flow within blood vessels in the vicinity of the aneurysm might be relevant for the pathogenesis and development of this malformation.}, keywords = {chaotic advection; Fractals; Computational fluid dynamics; Passive tracers; Cerebral aneurysm; Information dimension}, year = {2024}, pages = {397-412}, orcid-numbers = {Závodszky, Gábor/0000-0003-0150-0229; Károlyi, György/0000-0002-1021-9554; Szikora, István/0000-0003-3730-3278; Paál, György/0000-0003-1426-2215} } @article{MTMT:34721300, title = {The ENEN’s role in shaping the European nuclear education}, url = {https://m2.mtmt.hu/api/publication/34721300}, author = {Lazaro Pavel, Gabriel and Pesznyák, Csilla and Javier Elorza Tenreiro, Francisco and Starflinger, Joerg and Cizelj, Leon and Ambrosini, Walter}, doi = {10.1016/j.nucengdes.2024.112999}, journal-iso = {NUCL ENG DES}, journal = {NUCLEAR ENGINEERING AND DESIGN}, volume = {420}, unique-id = {34721300}, issn = {0029-5493}, year = {2024}, eissn = {1872-759X}, orcid-numbers = {Pesznyák, Csilla/0000-0001-5815-0974} } @article{MTMT:34596738, title = {Towards strategic agenda for European nuclear education, training, and knowledge management}, url = {https://m2.mtmt.hu/api/publication/34596738}, author = {Cizelj, Leon and Pesznyák, Csilla and Starflinger, Jörg and Pavel, Gabriel Lazaro and Wastin, Franck and Michailidou, Eirini}, doi = {10.1016/j.nucengdes.2024.113001}, journal-iso = {NUCL ENG DES}, journal = {NUCLEAR ENGINEERING AND DESIGN}, volume = {420}, unique-id = {34596738}, issn = {0029-5493}, year = {2024}, eissn = {1872-759X}, orcid-numbers = {Cizelj, Leon/0000-0002-8038-722X; Pesznyák, Csilla/0000-0001-5815-0974} } @article{MTMT:34580095, title = {Review of solutions developed for improving maneuvering flexibility in German, French and Russian PWRs targeting to explore future possibilities for the new VVER-1200 nuclear power plant units in Hungary}, url = {https://m2.mtmt.hu/api/publication/34580095}, author = {Szondy, Borbála Nóra and Bodnár, Balázs and Grossetête, Alain and Gain, Thibaut and Aszódi, Attila}, doi = {10.1016/j.nucengdes.2024.112965}, journal-iso = {NUCL ENG DES}, journal = {NUCLEAR ENGINEERING AND DESIGN}, volume = {419}, unique-id = {34580095}, issn = {0029-5493}, year = {2024}, eissn = {1872-759X}, pages = {112965}, orcid-numbers = {Szondy, Borbála Nóra/0009-0002-0458-8000} } @article{MTMT:34579996, title = {Education methods of the European nuclear experimental educational platform}, url = {https://m2.mtmt.hu/api/publication/34579996}, author = {Čerba, Štefan and Haščík, Ján and Lüley, Jakub and Vrban, Branislav and Radulović, Vladimir and Jazbec, Anže and Snoj, Luka and Sklenka, Ľubomír and Miglierini, Marcel and Czifrus, Szabolcs and Tormási, Attila and Cagnazzo, Marcella and Böck, Helmuth and Villa, Mario}, doi = {10.1016/j.nucengdes.2024.112973}, journal-iso = {NUCL ENG DES}, journal = {NUCLEAR ENGINEERING AND DESIGN}, volume = {420}, unique-id = {34579996}, issn = {0029-5493}, year = {2024}, eissn = {1872-759X}, orcid-numbers = {Čerba, Štefan/0000-0002-4065-3976} } @article{MTMT:34568144, title = {PIV measurements for VVER pressurized water reactor rod bundle geometries including spacer grids for CFD model validations}, url = {https://m2.mtmt.hu/api/publication/34568144}, author = {Orosz, Gergely Imre and Kacz, Dániel and Magyar, Boglárka and Aszódi, Attila}, doi = {10.1016/j.nucengdes.2024.112938}, journal-iso = {NUCL ENG DES}, journal = {NUCLEAR ENGINEERING AND DESIGN}, volume = {419}, unique-id = {34568144}, issn = {0029-5493}, abstract = {A PIV (Particle Image Velocimetry) test facility called PIROUETTE (PIv ROd bUndlE Test faciliTy at bmE) has been built at BME (Budapest University of Technology and Economics) NTI (Institute of Nuclear Techniques). The facility is capable of investigating of flow processes under isothermal conditions with different type triangular lattice seven-rod bundles. The currently investigated rod bundle is featuring spacer grids and hydraulic conditions related to the VVER-1000 and VVER-1200 fuel assemblies. This small bundle of 7 rods is a geometrically accurate representation of a piece of the real reactor's fuel bundle, including the spacer grids. These spacer grids were 3D printed from a special type of plastic for the PIV experiments in order to reproduce the real geometry inside the assemblies as accurately as possible. The effect of the spacer grids with vanes (which are located on the spacer grid belt section) was investigated using different test grid configurations. The measurements aimed to capture high resolution flow fields inside the rod bundle with MIR (Matching Index of Refraction), in order to enable the flow measurements even within the bundle, where usually the flow field is not visible. For this purpose, the geometry was manufactured using special transparent materials. The detailed, high resolution experimental data could be used for CFD (Computational Fluid Dynamics) benchmarking and code validation, and therefore can serve the further safe and reliable operation of these reactors. The results include velocity field, velocity standard deviations (RMS), Reynolds stress and turbulent kinetic energy distributions extracted from the measured data. The attachments include the 3D model of the experimental geometry, measured velocity distributions and other parameters along various monitor lines. © 2024 The Author(s)}, keywords = {KINETICS; IMAGE VELOCIMETRY; GEOMETRY; Refractive index; Reynolds number; Kinetic energy; Computational fluid dynamics; flow visualization; Pressurized water reactors; Velocity measurement; particle image velocimetry; particle image velocimetry; Flow fields; Velocity distribution; Test facilities; 3D printing; Fuel assembly; Fuel assembly; Velocimeters; index of refraction; Matching index; CFD modell validation; Matching index of refraction; PIROUETTE system; VVER-1200 reactor; Computational fluid dynamic modell validation; Matching index of refraction; Particle images; PIROUETTE system; VVER-1200 reactor}, year = {2024}, eissn = {1872-759X}, orcid-numbers = {Kacz, Dániel/0000-0002-6217-0481} }