Validation of a CFD Condensation Model Based on Heat and Mass Transfer Analogy by TOSQAN Facility ISP47 Test

Author(s):  
Matteo Bucci ◽  
Walter Ambrosini ◽  
Nicola Forgione ◽  
Francesco Oriolo ◽  
Sandro Paci

The content of this paper is focused on a computational fluid dynamics analysis of the test performed within the facility TOSQAN as a part of the International Standard Problem 47 (ISP 47). The aim of the study is to contribute to the understanding of the heat and mass transfer mechanisms and to check the possibility to use a commercial CFD code for simulating the mass transfer phenomena of interest in nuclear reactor containment design and safety analysis. In this aim, the FLUENT 6.2 code has been used. The effect of the condensation rate onto the vessel walls was simulated by appropriate source terms introduced by user-defined subroutines into the mass, energy and momentum balance equations. In the paper the time trends of the average temperature and pressure of the atmosphere inside the TOSQAN vessel have been compared with the available experimental data, obtaining a good agreement. Spatial profiles have been also analysed and compared with the experimental ones for the main physical variables in the first, second and fourth steady-state phases which the test consists of.

2020 ◽  
Vol 9 (4) ◽  
pp. 321-335
Author(s):  
Wan Nura’in Nabilah Noranuar ◽  
Ahmad Qushairi Mohamad ◽  
Sharidan Shafie ◽  
Ilyas Khan ◽  
Lim Yeou Jiann

Non-coaxial rotation system has encountered in various fields such as engineering field in designing advanced cooling and heating system, food processing and mixer machines. In the present study, the effect of the non-coaxial rotation of a vertical disk on the heat and mass transfer of Newtonian nanofluids in a porous medium is analytically discussed. The influence of the magnetic field and thermal radiation is also taken into the consideration. Two different types of nanofluids which are single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) with water as the base fluid are analyzed and compared. Suitable dimensionless variables are utilized to convert the governing partial differential equations associated with the initial and boundary conditions into the dimensionless form. Then, the exact solutions of the dimensionless governing equations are calculated by using the Laplace transform method. A limiting case study of the obtained analytical solutions is constructed to compare with the previously published results to verify its validity. The distributions of the velocity, temperature, and concentration along with the Skin friction, Nusselt number, and Sherwood number due to the variation of the pertinent parameters are displayed and scrutinized through graphs and tables. In the frame of non-coaxial rotation, the nanofluid with the SWCNTs nanoparticles have illustrated a higher rate of heat transfer as compared to MWCNTs nanofluid. Moreover, the heat transmission in the nanofluid has been enhanced by increasing the volume fraction of the nanoparticle and also the intensity of the radiation. This suggests that heating or cooling in a system such as a nuclear reactor can be improved by properly selecting the type of the nanofluid and also the volume fraction of the nanoparticle.


2017 ◽  
Vol 10 ◽  
pp. 93-106 ◽  
Author(s):  
M.K. Teixeira de Brito ◽  
D.B. Teixeira de Almeida ◽  
A.G. Barbosa de Lima ◽  
L. Almeida Rocha ◽  
E. Santana de Lima ◽  
...  

This work aims to study heat and mass transfer in solids with parallelepiped shape with particular reference to drying process. A transient three-dimensional mathematical model based on the Fick ́s and Fourier ́s Laws was developed to predict heat and mass transport in solids considering constant physical properties and convective boundary conditions at the surface of the solid. The analytical solution of the governing equations was obtained using the method of separation of variables. The study was applied in the drying of common ceramic bricks. Predicted results of the heating and drying kinetics and the moisture and temperature distributions inside the material during the process, are compared with experimental data and good agreement was obtained. It has been found that the vertices of the solid dry and heat first. This provokes thermal and hydric stresses inside the material, which may compromise the quality of the product after drying.


Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1176
Author(s):  
Siti Nur Alwani Salleh ◽  
Norfifah Bachok ◽  
Fadzilah Md Ali ◽  
Norihan Md Arifin

The present paper concentrates on the second-order slip flow over a moving thin needle in a nanofluid. The combined effects of thermophoresis and Brownian motion are considered to describe the heat and mass transfer performance of nanofluid. The resulting system of equations are obtained using similarity transformations and being executed in MATLAB software via bvp4c solver. The physical characteristics of embedded parameters on velocity, temperature, concentration, coefficient of skin friction, heat and mass transfer rates are demonstrated through a graphical approach and are discussed in detail. The obtained outcomes are validated with the existing works and are found to be in good agreement. It is shown that, for a specific domain of moving parameter, dual solutions are likely to exist. The stability analysis is performed to identify the stability of the solutions gained, and it is revealed that only one of them is numerically stable. The analysis indicated that the percentage of increment in the heat and mass transfer rates from no-slip to slip condition for both thin and thick surfaces of the needle ( a = 0.1 and a = 0.2 ) are 10.77 % and 12.56 % , respectively. Moreover, the symmetric behavior is noted for the graphs of reduced heat and mass transfer when the parameters N b and N t are the same.


2014 ◽  
Vol 13 (2) ◽  
pp. 41
Author(s):  
B. I. Favacho ◽  
J. R. P. Vaz ◽  
A. L. A. Mesquita

The navigation in Amazon region is very important due to the length of navigable rivers and the lack of alternative road network, as well as being a form of transportation costless for the flow of agricultural and manufacturing production. This kind of transportation present social, economic and technological importance for this region. Thus, this work objective to develop a mathematical approach for the marine propellers design, using a formulation for chord and pitch angle optimization, taken into account the equations of mass, energy and momentum balance for the theoretical calculation of thrust and torque relationships on an annular control volume, ie, the mathematical model is based in the Blade Element Momentum (BEM) theory. The proposed hydrodynamic model present low computational cost and it is easy to implement. The results are compared with classical Glauert's theory and the experimental data of the Wageningen B3-50 propeller, presenting good agreement.


2015 ◽  
Vol 48 ◽  
pp. 69-76 ◽  
Author(s):  
C.E.B. Romanini ◽  
V. Exadaktylos ◽  
S.W. Hong ◽  
Q. Tong ◽  
I. McGonnell ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
H. Romero-Paredes ◽  
F. J. Valdés-Parada ◽  
G. Espinosa-Paredes

This paper presents, the numerical analysis of heat and mass transfer during hydrogen generation in an array of fuel cylinder bars, each coated with a cladding and a steam current flowing outside the cylinders. The analysis considers the fuel element without mitigation effects. The system consists of a representative periodic unit cell where the initial and boundary-value problems for heat and mass transfer were solved. In this unit cell, we considered that a fuel element is coated by a cladding with steam surrounding it as a coolant. The numerical simulations allow describing the evolution of the temperature and concentration profiles inside the nuclear reactor and could be used as a basis for hybrid upscaling simulations.


1965 ◽  
Vol 87 (4) ◽  
pp. 499-506 ◽  
Author(s):  
R. F. Barron ◽  
L. S. Han

Heat and mass transfer rates were measured experimentally and compared with analytically developed correlations for frost formation on a vertical flat plate in free convection. The plate was cooled internally to cryogenic temperatures (−310 F or liquid nitrogen temperatures), and both the laminar and turbulent flow regimes were investigated. In the laminar flow correlation, the effects of thermal diffusion and diffusion thermoeffect were included. The analytical and experimental heat transfer rates were in good agreement; however, the mass transfer results were affected by the presence of macromolecules of frost within the boundary layer.


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