Defect equilibria and thermophysical properties of CeO 2‐ x based on experimental data and DFT calculation result

2021 ◽  
Author(s):  
Masashi Watanabe ◽  
Hiroki Nakamura ◽  
Kiichi Suzuki ◽  
Masahiko Machida ◽  
Masato Kato
Keyword(s):  
Experimental Data ◽  
Thermophysical Properties ◽  
Calculation Result ◽  
Dft Calculation ◽  
Defect Equilibria

Enhanced Condensation Heat-Transfer on Mini or Low Fin Tubes

2006 ◽  
Author(s):  
Adrian Briggs
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermophysical Properties ◽  
Heat Transfer Performance ◽  
Three Dimensional ◽  
Transfer Performance ◽  
Transfer Enhancement ◽  
Shell Side ◽  
Wide Range ◽  
Fin Tubes

This paper presents an overview of the use of low or mini-fin tubes for improving heat-transfer performance in shell-side condensers. The paper concentrates on, but is not limited to, the experimental and theoretical program in progress at Queen Mary, University of London. This work has so far resulted in an extensive data base of experimental data for condensation on single tubes, covering a wide range of tube geometries and fluid thermophysical properties and in the development of a simple to use model which predicts the majority of this data to within 20%. Work is progressing on the effects of vapor shear and on three-dimensional fin profiles; the later having shown the potential for even higher heat-transfer enhancement.

An Analytical Investigation of Free Convection Heat Transfer to Supercritical Water

1970 ◽  
Vol 92 (3) ◽  
pp. 345-350 ◽  
Author(s):  
E. S. Nowak ◽  
A. K. Konanur
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Free Convection ◽  
Supercritical Water ◽  
Thermophysical Properties ◽  
Convection Heat Transfer ◽  
Analytical Investigation ◽  
Convection Heat ◽  
Free Convection Heat ◽  
Vertical Flat Plate

Heat transfer to supercritical water (at 3400 psia in the pseudocritical region) by stable laminar free convection from an isothermal, vertical flat plate was analytically investigated. The actual variations with temperature of all or some of the thermophysical properties of supercritical water were taken into consideration. Fair agreement was found between the analytical values of this paper and existing experimental data.

scholarly journals Boiling Heat Transfer Evaluation in Nanoporous Surface Coatings

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3383
Author(s):  
Uzair Sajjad ◽  
Imtiyaz Hussain ◽  
Muhammad Imran ◽  
Muhammad Sultan ◽  
Chi-Chuan Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Deep Learning ◽  
Thermophysical Properties ◽  
Boiling Heat Transfer ◽  
Parameters Estimation ◽  
Learning Method ◽  
Working Fluids ◽  
Coated Surfaces ◽  
Nanoporous Surfaces

The present study develops a deep learning method for predicting the boiling heat transfer coefficient (HTC) of nanoporous coated surfaces. Nanoporous coated surfaces have been used extensively over the years to improve the performance of the boiling process. Despite the large amount of experimental data on pool boiling of coated nanoporous surfaces, precise mathematical-empirical approaches have not been developed to estimate the HTC. The proposed method is able to cope with the complex nature of the boiling of nanoporous surfaces with different working fluids with completely different thermophysical properties. The proposed deep learning method is applicable to a wide variety of substrates and coating materials manufactured by various manufacturing processes. The analysis of the correlation matrix confirms that the pore diameter, the thermal conductivity of the substrate, the heat flow, and the thermophysical properties of the working fluids are the most important independent variable parameters estimation under consideration. Several deep neural networks are designed and evaluated to find the optimized model with respect to its prediction accuracy using experimental data (1042 points). The best model could assess the HTC with an R2 = 0.998 and (mean absolute error) MAE% = 1.94.

Positron annihilation in mordenite zeolite

2021 ◽  
Vol 6 (1) ◽  
pp. 50-55
Author(s):  
Hoa Lang Trinh ◽  
Van Tao Chau ◽  
Hoang Lam Le ◽  
Quoc Dung Tran
Keyword(s):  
Experimental Data ◽  
Positron Annihilation ◽  
Dft Calculation ◽  
Positron Lifetime ◽  
Theoretical Study ◽  
Material Structure ◽  
Accuracy Analysis ◽  
Complicated Structure ◽  
Theoretical Results ◽  
Selection Of

The theoretical study of the positron annihilation in complex material such as zeolite is greatly significant to support and increase the accuracy analysis of the material structure from the experimental data of the positron annihilation. The mordenite zeolite is a big and complicated structure consisting of channels and cavities. The analysis of the mordenite structure is studied by the PALS so depending on the selection of the positron lifetime components of the positron annihilation spectra fitting methods. Therefore, these positron life times in on TO4, Na, Ca, K, Fe, H2O and the rings which form the channels and cavities are sophisticatedly studied by the DFT calculation using Ab-initio. The mordenite and modified mordenite zeolite structures are precisely analyzed, and the physical behaviors of the positron in these are more understood by these theoretical results.

Prediction of Forming Limit of Sheet Metal Based on Stören-Rice Model

2011 ◽  
Vol 221 ◽  
pp. 205-210
Author(s):  
Wei Gang Guo ◽  
Jia Ming Chen ◽  
Hui Min Li ◽  
Li Dong Shao
Keyword(s):  
Experimental Data ◽  
Sheet Metal ◽  
Calculation Result ◽  
Anisotropy Parameter ◽  
Yield Function ◽  
Limit Strain ◽  
Forming Limit ◽  
Left Hand ◽  
A Value ◽  
The Right

On the basis of Storen-Rice model, the limit strain formula is derived by introducing the plasticity constitutive relation coupling Logan-Hosford yield function. Limit strain of AL6111-T4 and AL2028 is calculated and compared with experimental data. The effect of index a of yield function, anisotropy parameter r on the calculation result is discussed. Index a has a significant effect on the right hand side(RHS) limit strain, while it has less relation with left hand side(LHS) limit strain. The RHS limit strain is smaller while a-value gets larger. Good correlation between the calculation result and experimental data is indicated when a-value equals to 4. The RHS limit strain is smaller while r gets larger when a equals to 2, while it has less relation with r when a equals to 4 or 6.

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.

scholarly journals Validation and Optimization of Thermophysical Properties for Thermal Conductivity and Viscosity of Nanofluid Engine Oil using Neural Network

2020 ◽  
Vol 3 (1) ◽  
pp. 53-60
Author(s):  
Amin Moslemi Petrudi ◽  
Masoud Rahmani
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
Optimization Algorithm ◽  
Thermophysical Properties ◽  
Volume Fraction ◽  
Engine Oil ◽  
Coefficient Of Determination ◽  
Neural Network Modeling ◽  
Nsga Ii

In this study, the thermophysical properties of thermal conductivity and viscosity of a motor oil nanofluid were investigated using experimental data and artificial neural network. NSGA II optimization algorithm was used to maximize thermal conductivity and minimum viscosity with changes in temperature and volume fraction of nanofluids. Also, to obtain the viscosity and thermal conductivity values in terms of nanofluid temperature and volume fraction with 174 experimental data, neural network modeling was performed. Input data include temperature and volume fraction, and output is viscosity and thermal conductivity. Various indices such as R squared and Mean Square Error (MSE) have been used to evaluate the accuracy of modeling in the prediction of viscosity and thermal conductivity of nanofluids. The coefficient of determination R squared is 0.9989 indicating acceptable agreement with the experimental data. In order to optimize and finally results as an objective function, the optimization algorithm is presented and the Parto front and its corresponding optimum points are presented where the maximum optimization results of thermal conductivity and viscosity occur at 1% volume fraction.

Measuring thermophysical properties of materials by the method of a linear pulse heat source with processing a large number of experimental data

Metrologiya ◽  
2019 ◽  
pp. 56-66
Author(s):  
S.V. Ponomarev ◽  
E.V. Bulanov ◽  
V.O. Bulanova ◽  
A.G. Divin ◽  
S.S. S. Al-Busaidi
Keyword(s):  
Experimental Data ◽  
Heat Source ◽  
Thermophysical Properties ◽  
Pulse Heat ◽  
Linear Pulse ◽  
Properties Of Materials
Sign in / Sign up

Export Citation Format

Share Document