scholarly journals Numerical Simulations with RELAP5-3D and RELAP5/mod3.3 of the Second Experimental Campaign on In-Box LOCA Transients for HCLL TBS

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4544
Author(s):  
Alessandro Venturini ◽  
Marco Utili ◽  
and Nicola Forgione
Keyword(s):  
Experimental Data ◽  
Wave Propagation ◽  
Literature Review ◽  
Numerical Simulations ◽  
Thermophysical Properties ◽  
Pressure Wave ◽  
Experimental Results ◽  
Experimental Campaign ◽  
Maximum Value ◽  
Lead Bismuth Eutectic

In-box LOCA was identified as one of the worst accidental scenarios for the HCLL TBS (Helium Cooled Lithium-Lead Test Blanket System). Aiming to experimentally analyze the consequences of this transient, ENEA designed and built THALLIUM (Test HAmmer in Lead LIthiUM), a facility that reproduces the LiPb loop of the HCLL TBS. Two experimental campaigns were carried out by simulating the rupture of a stiffening plate and the related helium injection in the LiPb loop. The obtained experimental data were used to check the capabilities of RELAP5 system code to reproduce the pressure wave propagation that follows this accident. The first simulations were made with RELAP5-3D using LBE (Lead–Bismuth Eutectic) as a system fluid, as the thermophysical properties of LiPb are tabulated only up to a maximum value of 40 bar in this version of the code. Then, LiPb properties were implemented in RELAP5/mod3.3, after selecting the proper correlations from a literature review. This work summarizes the numerical simulations of the second experimental campaign, which was simulated with both versions of the code. The simulations highlight that the code is able to accurately reproduce the experimental results and that RELAP5-3D is slightly more precise than RELAP5/mod3.3 in predicting the pressure trends.

Experimental campaign on pressure wave propagation in LLE

2018 ◽  
Vol 136 ◽  
pp. 809-814 ◽  
Author(s):  
A. Venturini ◽  
M. Utili ◽  
D. Martelli ◽  
I. Ricapito ◽  
A. Malavasi
Keyword(s):  
Wave Propagation ◽  
Pressure Wave ◽  
Experimental Campaign

Numerical Study on Hydraulic Performances of Pump as Turbine With Forward-Curved Blades

2014 ◽  
Author(s):  
Tao Wang ◽  
Fanyu Kong ◽  
Sunsheng Yang ◽  
Yanxia Fu
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Numerical Simulations ◽  
Turbulence Model ◽  
Numerical Study ◽  
Internal Flow ◽  
Hydraulic Turbine ◽  
Experimental Results ◽  
Computational Accuracy ◽  
Computational Stability

A reserved running centrifugal pump can work as a hydraulic turbine with its wide application in industrial energy recovery and the development of micro-hydraulic power. In order to improve the efficiency from the point of turbine working condition, the impeller with forward-curved blades was designed and the hydraulic performances were further analyzed based on the commercial software ANSYS CFX 12.0 in this study. Moreover, to improve the computational accuracy of numerical simulations on turbines, the grid number, the turbulence model, the circumferential flow distribution in the clearance between the volute and the impeller as well as the grid distribution in the boundary layer were considered. According grid independency analysis, the 1.2 million grids’ number was assumed for numerical simulations. Considering the consuming time and computational stability, as well as the accuracy of the CFD calculation, the k–ε turbulence model was chosen for further calculations. The shaft power and the efficiency of the turbine were more close to the experimental data as the whole computational flow domain in the clearance between the volute and the impeller was connected on the impeller domain. Compared with the performance curves with or without grids in the boundary layer, the boundary layer with grids used in the PAT during numerical simulations was more close to the experimental one. Compared with the experimental data, the H-Q curves of the hydraulic performances of the turbine with forward-curved blades predicted by CFD were positioned under the experimental one. With respect to the efficiency of the turbine, the various ranges of the efficiency is less than 5%, even there is some deviations between the CFD and experimental results. Therefore, the good agreement of the hydraulic performances between CFD and experimental results in present study indicates that the proposed numerical methods can adequately capture the internal flow in a hydraulic turbine with forward-curved blades, and can also provide a reliable reference for the design of hydraulic turbines.

scholarly journals Thermal conductivity difference between nanofluids and micro-fluids: Experimental data and theoretical analysis using mass difference scattering

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 3797-3807
Author(s):  
Fabrizio Iacobazzi ◽  
Gianpiero Colangelo ◽  
Marco Milanese ◽  
Risi de
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Theoretical Analysis ◽  
Metal Oxides ◽  
Mass Difference ◽  
Deionized Water ◽  
Experimental Results ◽  
Experimental Campaign ◽  
Nanometric Particles ◽  
Phonon Theory

In this work, an experimental campaign on different nanofluids and micro-fluids, obtained by the dispersion of three different metal oxides (CuO, ZnO, and TiO2) with diathermic oil or deionized water has been carried out, in order to extend phonon theory to liquids, as already done in a previous work on Al2O3. Thermal conductivity of stable samples was evaluated by time. The experimental results on thermal conductivity of stable micrometric and nanometric particles suspensions in oil and water showed a further proof of mass difference scattering phenomenon.

scholarly journals Classical Plasmonics: Wave Propagation Control at Subwavelength Scale

NANO ◽  
2015 ◽  
Vol 10 (07) ◽  
pp. 1530005 ◽  
Author(s):  
Víctor Coello ◽  
Cesar E. Garcia-Ortiz ◽  
Manuel Garcia-Mendez
Keyword(s):  
Wave Propagation ◽  
Numerical Simulations ◽  
Surface Plasmons ◽  
Surface Plasmon ◽  
Surface Plasmon Polaritons ◽  
Experimental Results ◽  
Paper Surface ◽  
Optical Images ◽  
Plasmon Polaritons ◽  
Beam Manipulation

In this paper, surface plasmons polariton propagation and manipulation is reviewed in the context of experiments and modeling of optical images. We focus our attention in the interaction of surface plasmon polaritons with arrays of micro-scatereres and nanofabricated structures. Numerical simulations and experimental results of different plasmonic devices are presented. Plasmonic beam manipulation opens up numerous possibilities for application in biosensing, nanophotonics, and in general in the area of surface optics properties.

Constitutive Relations for Superplastic Flow Modeling from Two Axial Loading Experiments

2010 ◽  
Vol 433 ◽  
pp. 319-323 ◽  
Author(s):  
A. Akhunovaa ◽  
Sergey A. Dmitriev ◽  
A.A. Kruglov ◽  
Rinat V. Safiullin
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Critical Analysis ◽  
Constitutive Relations ◽  
Axial Loading ◽  
Superplastic Forming ◽  
Experimental Results ◽  
Flow Modeling ◽  
Best Fit ◽  
Fitting Parameters

A critical analysis of approaches to find constitutive relations from the tests on uniaxial and two axial loading is presented. Then we report on the methodology of fitting parameters of constitutive relations for superplastic forming based on the results of cone cup and elongated wedge cup tests. Optimal cone and wedge angles are estimated analytically and also from the results of finite element simulations. Our methodology is based on comparison of the experimental results and the results of numerical simulations of the corresponding tests in frame of the commercial software such as ANSYS10.0 (ED). We carry out numerical simulations of the cone cup and the wedge cup tests for different sets of parameters of the chosen constitutive relation and different values of friction coefficient in order to reproduce the experimental results. The parameters corresponding to the best fit of the experimental data are then recommended for the use in computer simulations of the superplastic forming of commercial products.

COMPARISON OF NUMERICAL SIMULATIONS WITH EXPERIMENTAL DATA FOR VERTICAL ANNULAR AND CHURN GAS-LIQUID FLOWS

2020 ◽  
Author(s):  
Larissa Steiger de Freitas ◽  
Marcus Vinícius Canhoto Alves ◽  
Rafael Rodrigues Francisco
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Liquid Flows

Experimental Study on the Specific Heat Capacity Measurement of Water-Based Al2O3-Cu Hybrid Nanofluid by using Differential Thermal Analysis Method

2019 ◽  
Vol 15 ◽  
Author(s):  
Andaç Batur Çolak ◽  
Oğuzhan Yıldız ◽  
Mustafa Bayrak ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermophysical Properties ◽  
Volume Concentration ◽  
Pure Water ◽  
Heat Capacity Measurement ◽  
Experimental Results ◽  
Hybrid Nanofluid ◽  
Capacity Measurement

Background: Researchers working in the field of nanofluid have done many studies on the thermophysical properties of nanofluids. Among these studies, the number of studies on specific heat are rather limited. In the study of the heat transfer performance of nanofluids, it is necessary to increase the number of specific heat studies, whose subject is one of the important thermophysical properties. Objective: The authors aimed to measure the specific heat values of Al2O3/water, Cu/water nanofluids and Al2O3-Cu/water hybrid nanofluids using the DTA method, and compare the results with those frequently used in the literature. In addition, this study focuses on the effect of temperature and volume concentration on specific heat. Method: The two-step method was used in the preparation of nanofluids. The pure water selected as the base fluid was mixed with the Al2O3 and Cu nanoparticles and Arabic Gum as the surfactant, firstly mixed in the magnetic stirrer for half an hour. It was then homogenized for 6 hours in the ultrasonic homogenizer. Results: After the experiments, the specific heat of nanofluids and hybrid nanofluid were compared and the temperature and volume concentration of specific heat were investigated. Then, the experimental results obtained for all three fluids were compared with the two frequently used correlations in the literature. Conclusion: Specific heat capacity increased with increasing temperature, and decreased with increasing volume concentration for three tested nanofluids. Cu/water has the lowest specific heat capacity among all tested fluids. Experimental specific heat capacity measurement results are compared by using the models developed by Pak and Cho and Xuan and Roetzel. According to experimental results, these correlations can predict experimental results within the range of ±1%.

scholarly journals LHR effects in nonducted whistler propagation – new observations and numerical modelling

2001 ◽  
Vol 19 (2) ◽  
pp. 147-157 ◽  
Author(s):  
F. Jiřiček ◽  
D. R. Shklyar ◽  
P. Třiska
Keyword(s):  
Wave Propagation ◽  
Numerical Modelling ◽  
Plasma Frequency ◽  
Cutoff Frequency ◽  
Lower Hybrid ◽  
Noise Band ◽  
Maximum Value ◽  
Lower Hybrid Resonance ◽  
Whistler Propagation ◽  
Lower Cutoff

Abstract. VLF-ELF broadband measurements onboard the MAGION 4 and 5 satellites at heights above 1 Re in plasmasphere provide new data on various known phenomena related to ducted and nonducted whistler wave propagation. Two examples are discussed: magnetospherically reflected (MR) whistlers and lower hybrid resonance (LHR) noise band. We present examples of rather complicated MR whistler spectrograms not reported previously and argue the conditions for their generation. Analytical consideration, together with numerical modelling, yield understanding of the main features of those spectrograms. LHR noise band, as well as MR whistlers, is a phenomenon whose source is the energy propagating in the nonducted way. At the plasmaspheric heights, where hydrogen (H+) is the prevailing ion, and electron plasma frequency is much larger than gyrofrequency, the LHR frequency is close to its maximumvalue in a given magnetic field. This frequency is well followed by the observed noise bands. The lower cutoff frequency of this band is somewhat below that maximum value. The reason for this, as well as the possibility of using the LHR noise bands for locating the plasma through position, are discussed.Key words. Magnetospheric physics (plasmasphere; wave propagation)

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