scholarly journals Study of heat and mass transfer control inside channel partially filled with a porous medium using nanofluids

2019 ◽  
pp. 460-460 ◽  
Author(s):  
Hamida Ben ◽  
Mohamed Massoudi ◽  
Riadh Marzouki ◽  
Lioua Kolsi ◽  
Mohammed Almeshaal ◽  
...  

The steady mixed convection of heat and mass transfer inside and outside a porous vertical wall is numerically studied. The porous wall, placed in a vertical channel, contains a solid phase, a nanofluid phase (Water-Al2O3 or Water-Cu) and gas phase. The effect of several physical quantities such as nanoparticle volume fraction, ambient temperature and initial nanofluid saturation on heat and mass transfer were investigated. Results reveal that the temperature of porous medium is decreased considerably with nanoparticle volume fraction. It has been also found that the heat and mass transfer are dramatically reduced using Water-Alumina nanofluid when compared with pure water.

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.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patakota Sudarsana Reddy ◽  
Paluru Sreedevi ◽  
Kavaturi Venkata Suryanarayana Rao

Purpose The purpose of this paper is to know the influence of heat generation/absorption and slip effects on heat and mass transfer flow of carbon nanotubes – water-based nanofluid over a rotating disk. Two types of carbon nanotubes, single and multi-walled, are considered in this analysis. Design/methodology/approach The non-dimensional system of governing equations is constructed using compatible transformations. These equations together with boundary conditions are solved numerically by using the most prominent Finite element method. The influence of various pertinent parameters such as magnetic parameter (0.4 – 1.0), nanoparticle volume fraction parameter (0.1 – 0.6), porosity parameter (0.3 – 0.6), radiation parameter (0.1 – 0.4), Prandtl number (2.2 – 11.2), space-dependent (−3.0 – 3.0), temperature-dependent (−3.0 – 1.5), velocity slip parameter (0.1 – 1.0), thermal slip parameter (0.1 – 0.4) and chemical reaction parameter (0.3 – 0.6) on nanofluids velocity, temperature and concentration distributions, as well as rates of velocity, temperature and concentration is calculated and the results are plotted through graphs and tables. Also, a comparative analysis is carried out to verify the validation of the present numerical code and found good agreement. Findings The results indicate that the temperature of the fluid elevates with rising values of nanoparticle volume fraction parameter. Furthermore, the rates of heat transfer rise from 4.8% to 14.6% when carbon nanotubes of 0.05 volume fraction are suspended into the base fluid. Originality/value The work carried out in this analysis is original and no part is copied from other sources.


2019 ◽  
Vol 26 ◽  
pp. 30-44
Author(s):  
Noureddine Messaoudi ◽  
Mohamed Nadjib Bouaziz ◽  
Hamza Ali Agha

In this work, the flow of a couple stress nanofluid in a vertical channel with heat and mass transfer in the presence of a magnetic field and taking account the Brownian motion, the thermophoresis as well as the effect of Soret and Dufour was simulated numerically using Matlab following the code bvp4c. The nonlinear partial differential equations governing this particular flow are transformed into a system of ordinary differential equations via the similarity technique. The influence of the parameters describing the behavior of the problem studied on the velocity, temperature, concentration and volume fraction fields of the nanoparticles, as well as on the coefficient of friction, Nusselt and Sherwood numbers, were highlighted for the end of the study. understand their effect on heat and mass transfer. The rheology of the nanofluid and the magnetic field have a strong impact on the velocity and temperature profiles, while the parameters of Brownian motion and thermophoresis promote heat transfer.


1990 ◽  
Vol 68 (9) ◽  
pp. 790-793 ◽  
Author(s):  
Yu. A. Buyevich ◽  
L. Y. Iskakova ◽  
V. V. Mansurov

A mushy region (a two-phase zone) between the solid and liquid phases occurs often in the process of solidification of a binary melt. An analysis of the structure of the mushy region, which includes the liquid, solid particles, and dendrites extending from the bulk solid surface, is suggested. The processes of heat and mass transfer in the mushy region are considered on the basis of the small parameter method. The analysis leads to equations governing unsteady heat and mass transfer with internal heat, and mass sources within the mushy region, and it includes the condition for the absence of supercooling (the condition for the zone quasi-equilibrium), convection being neglected. The temperature, concentration of solute, and solid phase volume fraction are found. On the basis of this solution a new model of the process is formulated. Within the scope of this model the mushy region is replaced by a liquid–solid interface with discontinuous boundary conditions.


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