scholarly journals Thermogravitational Convection of Hybrid Nanofluid in a Porous Chamber with a Central Heat-Conducting Body

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 593 ◽  
Author(s):  
Mikhail A. Sheremet ◽  
Dalia Sabina Cimpean ◽  
Ioan Pop

A problem with the thermogravitational energy transference of a hybrid nanofluid (Al2O3-SiO2/H2O) in a porous space with a central heat-conducting body has been presented and numerical analysis has been performed. Governing equations, transformed in terms of non-dimensional parameters, have been solved by a developed numerical algorithm based on the finite difference technique. The behavior of streamlines and isotherms was investigated, and the impact of various important characteristics is discussed. The variation in the average and local Nusselt numbers was studied; by selecting various appropriate nano-sized particle combinations in hybrid nanosuspension, the desired energy transport strength could be obtained. The results were compared and successfully validated with previous reported numerical and experimental data from the literature.

2021 ◽  
Author(s):  
Obaid Ullah Mehmood ◽  
Sehrish Bibi ◽  
Dzuliana F. Jamil ◽  
Salah Uddin ◽  
Rozaini Roslan ◽  
...  

Abstract The main theme of this paper is to analyze the effects of concentric catheterization to the diseased arterial segment having both stenosis and aneurysm along its boundary. Fractional second grade hybrid nanofluid model is under consideration. Governing equations are formulated and further linearized for both cases of mild stenosis and aneurysm. Precise articulations for various important flow characteristics heat transfer, hemodynamic velocity, wall shear stress and resistance impedance are attained. Graphical portrayals for the impact of the significant parameters on the flow attributes have been devised and talked about. The worldwide conduct of blood has been examined using an instantaneous streamlines pattern. The present concept plans to be of use in medical regime for the drug conveyance system and biomedicines.


2005 ◽  
Vol 02 (03) ◽  
pp. 431-450 ◽  
Author(s):  
A. MEZRHAB ◽  
H. BOUALI ◽  
C. ABID

In this paper, we present a numerical study of the radiation-natural convection interactions in a differentially heated enclosure, within which a centered, squared, heat-conducting body generates heat. A specifically developed numerical model based on the finite-volume method and the SIMPLER algorithm is used for the solution of the governing equations. The working fluid (air) is perfectly transparent to the radiation. The Rayleigh number Ra and the temperature-difference ratio ΔT* were varied parametrically. For Pr = 0.71, the results obtained show that: (i) The isotherms and streamlines are strongly affected by the radiation exchange at high Rayleigh numbers (Ra ≥ 106), (ii) the temperature of the inner body decreases under the radiation exchange effect, (iii) for a constant Ra, the average Nusselt number at the hot and cold walls (Nuh and Nuc) vary linearly with increasing ΔT*: Nuh decreases with ΔT* while Nuc increases with ΔT*. Furthermore, the radiation exchange increases both average Nusselt numbers Nuh and Nuc, especially at Ra ≥ 105, and consequently, [Formula: see text] increases.


Heat Transfer ◽  
2021 ◽  
Author(s):  
Assad Ayub ◽  
Adil Darvesh ◽  
Gilder C. Altamirano ◽  
Zulqurnain Sabir

Fluids ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 138
Author(s):  
Ali Rehman ◽  
Zabidin Salleh

This paper analyses the two-dimensional unsteady and incompressible flow of a non-Newtonian hybrid nanofluid over a stretching surface. The nanofluid formulated in the present study is TiO2 + Ag + blood, and TiO2 + blood, where in this combination TiO2 + blood is the base fluid and TiO2 + Ag + blood represents the hybrid nanofluid. The aim of the present research work is to improve the heat transfer ratio because the heat transfer ratio of the hybrid nanofluid is higher than that of the base fluid. The novelty of the recent work is the approximate analytical analysis of the magnetohydrodynamics mixed non-Newtonian hybrid nanofluid over a stretching surface. This type of combination, where TiO2+blood is the base fluid and TiO2 + Ag + blood is the hybrid nanofluid, is studied for the first time in the literature. The fundamental partial differential equations are transformed to a set of nonlinear ordinary differential equations with the guide of some appropriate similarity transformations. The analytical approximate method, namely the optimal homotopy analysis method (OHAM), is used for the approximate analytical solution. The convergence of the OHAM for particular problems is also discussed. The impact of the magnetic parameter, dynamic viscosity parameter, stretching surface parameter and Prandtl number is interpreted through graphs. The skin friction coefficient and Nusselt number are explained in table form. The present work is found to be in very good agreement with those published earlier.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anwar Saeed ◽  
Muhammad Jawad ◽  
Wajdi Alghamdi ◽  
Saleem Nasir ◽  
Taza Gul ◽  
...  

AbstractThis work investigates numerically the solution of Darcy–Forchheimer flow for hybrid nanofluid by employing the slip conditions. Basically, the fluid flow is produced by a swirling disk and is exposed to thermal stratification along with non-linear thermal radiation for controlling the heat transfer of the flow system. In this investigation, the nanoparticles of titanium dioxide and aluminum oxide have been suspended in water as base fluid. Moreover, the Darcy–Forchheimer expression is used to characterize the porous spaces with variable porosity and permeability. The resulting expressions of motion, energy and mass transfer in dimensionless form have been solved by HAM (Homotopy analysis method). In addition, the influence of different emerging factors upon flow system has been disputed both theoretically in graphical form and numerically in the tabular form. During this effort, it has been recognized that velocities profiles augment with growing values of mixed convection parameter while thermal characteristics enhance with augmenting values of radiation parameters. According to the findings, heat is transmitted more quickly in hybrid nanofluid than in traditional nanofluid. Furthermore, it is estimated that the velocities of fluid $$f^{\prime}\left( \xi \right),g\left( \xi \right)$$ f ′ ξ , g ξ are decayed for high values of $$\phi_{1} ,\phi_{2} ,\,Fr$$ ϕ 1 , ϕ 2 , F r and $$k_{1}$$ k 1 factors.


2021 ◽  
Vol 60 (3) ◽  
pp. 3047-3056 ◽  
Author(s):  
Farwa Haider ◽  
Tasawar Hayat ◽  
Ahmed Alsaedi

2021 ◽  
Vol 11 (11) ◽  
pp. 4934
Author(s):  
Viola Rossano ◽  
Giuliano De Stefano

Computational fluid dynamics was employed to predict the early stages of the aerodynamic breakup of a cylindrical water column, due to the impact of a traveling plane shock wave. The unsteady Reynolds-averaged Navier–Stokes approach was used to simulate the mean turbulent flow in a virtual shock tube device. The compressible flow governing equations were solved by means of a finite volume-based numerical method, where the volume of fluid technique was employed to track the air–water interface on the fixed numerical mesh. The present computational modeling approach for industrial gas dynamics applications was verified by making a comparison with reference experimental and numerical results for the same flow configuration. The engineering analysis of the shock–column interaction was performed in the shear-stripping regime, where an acceptably accurate prediction of the interface deformation was achieved. Both column flattening and sheet shearing at the column equator were correctly reproduced, along with the water body drift.


Heat Transfer ◽  
2021 ◽  
Author(s):  
Anthonysamy John Christopher ◽  
Nanjundan Magesh ◽  
Ramanahalli Jayadevamurthy Punith Gowda ◽  
Rangaswamy Naveen Kumar ◽  
Ravikumar Shashikala Varun Kumar

Author(s):  
Fan Gong ◽  
Yong Huang

The objective of this work is to investigate the flame stabilization mechanism and the impact of the operating conditions on the characteristics of the steady, lean premixed flames. It’s well known that the flame base is very important to the existence of a flame, such as the flame after a V-gutter, which is typically used in ramjet and turbojet or turbofan afterburners and laboratory experiments. We performed two-dimensional simulations of turbulent premixed flames anchored downstream of the heat-conducting V-gutters in a confined passage for kerosene-air combustion. The flame bases are symmetrically located in the shear layers of the recirculation zone immediately after the V-gutter’s trailing edge. The effects of equivalence ratio of inlet mixture, inlet temperature, V-gutter’s thermal conductivity and inlet velocity on the flame base movements are investigated. When the equivalence ratio is raised, the flame base moves upstream slightly and the temperature gradient dT/dx near the flame base increases, so the flame base is strengthened. When the inlet temperature is raised, the flame base moves upstream very slightly, and near the flame base dT/dx increases and dT/dy decreases, so the flame base is strengthened. As the V-gutter’s thermal conductivity increases, the flame base moves downstream, and the temperature gradient dT/dx near the flame base decreases, so the flame base is weakened. When the inlet velocity is raised, the flame base moves upstream, and the convection heat loss with inlet mixture increases, so the flame base is weakened.


Author(s):  
R.J. Punith Gowda ◽  
R. Naveenkumar ◽  
J.K. Madhukesh ◽  
B.C. Prasannakumara ◽  
Rama Subba Reddy Gorla

The flow-through various disk movement has wide range of applications in manufacturing processes like, computer storage equipment’s, rotating machines, electronic and various types of medical equipment’s. Inspired from these applications, here we scrutinised the consequences of homogeneous-heterogeneous reactions and uniform heat source/sink on the three-dimensional (3D) hybrid SWCNT-MWCNT’s flow on time dependent moving upward/downward rotating disk. The renowned innovation of this paper is the application of the hybrid nanofluid made up of SWCNT and MWCNT’s. Heat generation/absorption effect for the disk that does not move up or down creates a dual flow on the disk. Alternatively, the rotation and upright motion of the disk creates a 3D flow on the surface which has not been considered in the open literature. The modelled PDE’s are reduced in to ODE’s by opting suitable similarity variables and boundary constraints. Here, we used RKF-45 method to obtain the numerical approximations by adopting shooting technique. The analysis of rate of heat transfer is done through graphs. Further, change in velocity, thermal and concentration profiles for various non-dimensional parameters are deliberated briefly and illustrated with the help of suitable plots. The results reveal that, the, rise in values of homogeneous and heterogeneous reaction parameters improve the rate of reaction which results in reduction of the distribution rate and diminishes the concentration gradient. An increase in expansion/contraction parameter enhances the velocity and thermal gradients.


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