scholarly journals COUPLING OF nTRACER TO COBRA-TF FOR HIGH-FIDELITY ANALYSIS OF VVERs

2021 ◽  
Vol 247 ◽  
pp. 02008
Author(s):  
Marianna Papadionysiou ◽  
Kim Seongchan ◽  
Mathieu Hursin ◽  
Alexander Vasiliev ◽  
Hakim Ferroukhi ◽  
...  
Keyword(s):  
Steady State ◽  
High Resolution ◽  
Coupling Scheme ◽  
High Fidelity ◽  
Fuel Temperature ◽  
The Cross ◽  
Paul Scherrer

Paul Scherrer Institut is developing a high-resolution multi-physics core solver for VVER analysis. This work presents the preliminary stages of the development, specifically the coupling of the 3D pin-by-pin neutronic solver nTRACER to the sub-channel thermal-hydraulic code COBRA-TF for single assembly multi-physics steady state calculations. The coupling scheme and the modifications performed in the codes are described in details. The results of the coupled nTRACER/COBRA-TF calculations are compared to the ones of a standalone nTRACER calculation where the feedbacks are provided by a simplified 1D thermal-hydraulic solver. The agreement is very good with fuel temperature differences around 10 K which can be attributed to the different correlations used in the various solvers. The cross-comparison of the two multi-physics computational routes serves as a preliminary verification of the coupling scheme developed between nTRACER and COBRA-TF.

SKETCH-N/ATHLET steady-state and dynamic coupling scheme verification on Kalinin-3 benchmark results

Kerntechnik ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. 265-273 ◽  
Author(s):  
V. I. Romanenko ◽  
V. G. Zimin ◽  
S. P. Nikonov ◽  
G. V. Tikhomirov ◽  
Y. Perin ◽  
...  
Keyword(s):  
Steady State ◽  
Coupling Scheme ◽  
Dynamic Coupling

Study of Temperature Effect on Servovalve-Controlled Fuel Metering Unit

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Bin Wang ◽  
Haocen Zhao ◽  
Ling Yu ◽  
Zhifeng Ye
Keyword(s):  
Steady State ◽  
Temperature Variation ◽  
Dynamic Characteristics ◽  
Numerical Study ◽  
Step Response ◽  
Fuel Temperature ◽  
Wide Range ◽  
Fuel Rate ◽  
Testing Condition ◽  
The Given

It is usual that fuel system of an aero-engine operates within a wide range of temperatures. As a result, this can have effect on both the characteristics and precision of fuel metering unit (FMU), even on the performance and safety of the whole engine. This paper provides theoretical analysis of the effect that fluctuation of fuel temperature has on the controllability of FMU and clarifies the drawbacks of the pure mathematical models considering fuel temperature variation for FMU. Taking the electrohydraulic servovalve-controlled FMU as the numerical study, simulation in AMESim is carried out by thermal hydraulic model under the temperatures ranged from −10 to 60 °C to confirm the effectiveness and precision of the model on the basis of steady-state and dynamic characteristics of FMU. Meanwhile, the FMU testing workbench with temperature adjustment device employing the fuel cooler and heater is established to conduct an experiment of the fuel temperature characteristics. Results show that the experiment matches well with the simulation with a relative error no more than 5% and that 0–50 °C fuel temperature variation produces up to 5.2% decrease in fuel rate. In addition, step response increases with the fuel temperature. Fuel temperature has no virtual impact on the steady-state and dynamic characteristics of FMU under the testing condition in this paper, implying that FMU can operate normally in the given temperature range.

scholarly journals Generation and robustness of quantum entanglement in spin graphs

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jan Riegelmeyer ◽  
Dan Wignall ◽  
Marta P. Estarellas ◽  
Irene D’Amico ◽  
Timothy P. Spiller
Keyword(s):  
Quantum Information Processing ◽  
Bell State ◽  
Spin Chains ◽  
Coupling Scheme ◽  
High Fidelity ◽  
Coupling Ratio ◽  
Entanglement Generation ◽  
Fabrication Errors ◽  
Coupling Strengths ◽  
Hardware Platforms

AbstractEntanglement is a crucial resource for quantum information processing, and so protocols to generate high-fidelity entangled states on various hardware platforms are in demand. While spin chains have been extensively studied to generate entanglement, graph structures also have such potential; however, only a few classes of graphs have been explored for this specific task. In this paper, we apply a particular coupling scheme involving two different coupling strengths to a graph of two interconnected $$3\times 3$$ 3 × 3 square graphs such that it effectively contains three defects. We show how this structure allows generation of a Bell state whose fidelity depends on the chosen coupling ratio. We apply partitioned graph theory in order to reduce the dimension of the graph and show that, using a reduced graph or a reduced chain, we can still simulate the same protocol with identical dynamics. Finally, we investigate how fabrication errors affect the entanglement generation protocol and how the different equivalent structures are affected, finding that for some specific coupling ratios they are extremely robust.

Wirkungsquerschnitte der Photoabsorption und Photoionisation des N2-Moleküls

1969 ◽  
Vol 24 (12) ◽  
pp. 1941-1952
Author(s):  
F.J. Comes ◽  
K.W. Weber
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Ionization Probability ◽  
Nitrogen Molecule ◽  
Strong Variation ◽  
Radiationless Transitions ◽  
Continuous Absorption ◽  
The Cross

AbstractThe cross sections of photoabsorption and photoionization of the nitrogen molecule have been determined with high resolution (Δλ: 0.08 Å). The experiments demonstrate that the continuous absorption is overlapped by strong bands which are diffuse due to radiationless transitions. The competition of autoionization and predissociation leads to a strong variation of the ionization probability. Arguments are given to explain this behaviour of the nitrogen bands.

scholarly journals The identification of pika and hare through tricho-taxonomy (Mammalia: Lagomorpha)

2019 ◽  
Vol 11 (10) ◽  
pp. 14301-14308
Author(s):  
Manokaran Kamalakannan ◽  
Kailash Chandra ◽  
Joy Krishna De ◽  
Chinnadurai Venkatraman
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
Guard Hair ◽  
Key Characteristics ◽  
The Family ◽  
Family Level ◽  
The Cross ◽  
Level Identification ◽  
Oval Shape

The macroscopic and microscopic characters of dorsal guard hairs of Indian lagomorphs (four species of pikas and three species of hare) are described; the cuticular and medullary characters are similar between the species studied.  The cuticular and medullary characters, however, are dissimilar between the family Ochotonidae and Leporidae.  The cross-section of hair of the species had shown two identical shapes between the family Ochotonidae and Leporidae.  The cross-section was observed as an oval shape in all the four ochotonid species, whereas there was a dumb-bell shape in all three leporid species.  The hair of the Indian lagomorphs can easily be differentiated up to the family level on the basis of their unique cuticula, medulla and cross-section of the dorsal guard hair.  The high-resolution microphotographs and key characteristics of hair that are presented here can be used as an appropriate reference for family-level identification of Indian lagomorphs.

scholarly journals Accelerated and noise-resistant generation of high-fidelity steady-state entanglement with Rydberg atoms

2018 ◽  
Vol 97 (3) ◽  
Author(s):  
Ye-Hong Chen ◽  
Zhi-Cheng Shi ◽  
Jie Song ◽  
Yan Xia ◽  
Shi-Biao Zheng
Keyword(s):  
Steady State ◽  
Rydberg Atoms ◽  
High Fidelity

scholarly journals Planetary architectures in interacting stellar environments

2020 ◽  
Vol 496 (2) ◽  
pp. 1453-1470 ◽  
Author(s):  
Yi-Han Wang ◽  
Rosalba Perna ◽  
Nathan W C Leigh
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
Cross Sections ◽  
Velocity Dispersion ◽  
Planetary System ◽  
Star Clusters ◽  
Exoplanetary Systems ◽  
The Cross ◽  
Star Binary ◽  
Strong Scattering

ABSTRACT The discovery of exoplanetary systems has challenged some of the theories of planet formation, which assume unperturbed evolution of the host star and its planets. However, in star clusters the interactions with fly-by stars and binaries may be relatively common during the lifetime of a planetary system. Here, via high-resolution N-body simulations of star–planet systems perturbed by interlopers (stars and binaries), we explore the reconfiguration to the planetary system due to the encounters. In particular, via an exploration focused on the strong scattering regime, we derive the fraction of encounters that result in planet ejections, planet transfers, and collisions by the interloper star/binary, as a function of the characteristics of the environment (density, velocity dispersion), and for different masses of the fly-by star/binary. We find that binary interlopers can significantly increase the cross-section of planet ejections and collisions, while they only slightly change the cross-section for planet transfers. Therefore, in environments with high binary fractions, floating planets are expected to be relatively common, while in environments with low binary fractions, where the cross-sections of planet ejection and transfer are comparable, the rate of planet exchanges between two stars will be comparable to the rate of production of free-floating planets.

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