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Article
Publication date: 4 December 2018

Marjan Goodarzi, Saeed Javid, Ali Sajadifar, Mehdi Nojoomizadeh, Seyed Hossein Motaharipour, Quang-Vu Bach and Arash Karimipour

With respect to two new subjects, i.e. nanofluids and microchannels, in heat transfer systems and modern techniques used for building them, this paper aims to study on effect of…

Abstract

Purpose

With respect to two new subjects, i.e. nanofluids and microchannels, in heat transfer systems and modern techniques used for building them, this paper aims to study on effect of using aluminum oxide nanoparticles in non-Newtonian fluid of aqueous solution of carboxy-methyl cellulose in microtube and through application of different slip coefficients to achieve various qualities on surface of microtube.

Design/methodology/approach

Simultaneously, the effect of presence of nanoparticles and phenomenon of slip and temperature jump has been explored in non-Newtonian nanofluid in this essay. The assumption of homogeneity of nanofluid and fixed temperature of wall in microtube has been used in modeling processes.

Findings

The results have been presented as diagrams of velocity, temperature and Nusselt Number and the investigations have indicated that addition of nanoparticles to the base fluid and increase in microtube slip coefficient might improve rate of heat transfer in microtube.

Originality/value

The flow of non-Newtonian nanofluid of aqueous solution of carboxy methyl cellulose-aluminum oxide has been determined in a microtube for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 7 August 2020

Ali Akbar Abbasian Arani and Reza Moradi

Using turbulators, obstacles, ribs, corrugations, baffles and different tube geometry, and also various arrangements of these components have a noticeable effect on the shell and…

Abstract

Purpose

Using turbulators, obstacles, ribs, corrugations, baffles and different tube geometry, and also various arrangements of these components have a noticeable effect on the shell and tube heat exchangers (STHEs) thermal-hydraulic performance. This study aims to investigate non-Newtonian fluid flow characteristics and heat transfer features of water and carboxyl methyl cellulose (H2O 99.5%:0.5% CMC)-based Al2O3 nanofluid inside the STHE equipped with corrugated tubes and baffles using two-phase mixture model.

Design/methodology/approach

Five different corrugated tubes and two baffle shapes are studied numerically using finite volume method based on SIMPLEC algorithm using ANSYS-Fluent software.

Findings

Based on the obtained results, it is shown that for low-mass flow rates, the disk baffle (DB) has more heat transfer coefficient than that of segmental baffle (SB) configuration, while for mass flow rate more than 1 kg/s, using the SB leads to more heat transfer coefficient than that of DB configuration. Using the DB leads to higher thermal-hydraulic performance evaluation criteria (THPEC) than that of SB configuration in heat exchanger. The THPEC values are between 1.32 and 1.45.

Originality/value

Using inner, outer or inner/outer corrugations (outer circular rib and inner circular rib [OCR+ICR]) tubes for all mass flow rates can increase the THPEC significantly. Based on the present study, STHE with DB and OCR+ICR tubes configuration filled with water/CMC/Al2O3 with f = 1.5% and dnp = 100 nm is the optimum configuration. The value of THPEC in referred case was 1.73, while for outer corrugations and inner smooth, this value is between 1.34 and 1.57, and for outer smooth and inner corrugations, this value is between 1.33 and 1.52.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 23 June 2018

Sara I. Abdelsalam and Muhammad Mubashir Bhatti

The purpose of this paper is to study the variable magnetic field and endoscope effects on peristaltic blood flow of nanofluid containing TiO2 nanoparticles (NPs) through a porous…

Abstract

Purpose

The purpose of this paper is to study the variable magnetic field and endoscope effects on peristaltic blood flow of nanofluid containing TiO2 nanoparticles (NPs) through a porous annulus. The Prandtl fluid model is taken into account for the present flow. The mathematical modelling comprises the temperature, continuity, NP concentration, and equations of motion which are further simplified by taking a long peristaltic wave and creeping flow regime.

Design/methodology/approach

After using the long wavelength approximation, the obtained highly non-linear partial differential equations are solved using the homotopy perturbation scheme. The inclusion of the pertinent parameters is discussed mathematically and graphically for the pressure rise, friction forces, temperature profile, and concentration profile. The trapping phenomenon is also investigated with the help of contours.

Findings

Results show that the maximum velocity distribution exists near the centre of the annulus, whereas the average time flow boosts the velocity profile. It has also been shown that flow can pass readily without enormous pressure gradient imposed on the endoscope tube unlike the case of the slim section of the problem.

Practical implications

The nanofluids containing titanium NPs are increasingly utilised since such type of NPs is used by several manufacturers in sunscreen blockers and different types of endoscopy. In endoscopy, the variable magnetic field is used at the tip in order to detect or treat diseases. The NPs are used since they acquire specific thermal properties as compared with base fluids. The present study provides qualitative results showing the effect of inner tube of annulus on the fluid flow, the effect of variable magnetic field, and the change in the temperature profile on the flow field.

Originality/value

A new model is introduced that shows the utmost pressure that works against the positive peristaltic pump. It studies the blood flow that results in extremely non-linear partial differential equations that are solved by the homotopy perturbation method. The titanium NPs are being used in blocking the rays that penetrate the epidermis causing skin burns and short ultraviolet ageing rays that cause visible wrinkles, and thus are used in the manufacturing of sunscreens that are partially absorbed through the skin.

Details

Multidiscipline Modeling in Materials and Structures, vol. 14 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 14 November 2016

Muhammad Mubashir Bhatti, Tehseen Abbas and M.M. Rashidi

The purpose of this paper is to analyze theoretically the effects of thermal radiation with electrohydrodynamics through a Riga plate. An incompressible and irrotational fluid…

Abstract

Purpose

The purpose of this paper is to analyze theoretically the effects of thermal radiation with electrohydrodynamics through a Riga plate. An incompressible and irrotational fluid with constant density is taken into account. The governing flow problem is modeled with the help of linear momentum, thermal energy equation and nanoparticle concentration equation.

Design/methodology/approach

Numerical integration is used with the help of the shooting technique to examine the novel features of the velocity profile, temperature profile and nanoparticle concentration profile. The impact of all the emerging parameters is sketched with the help of graphs. The numerical values of local Nusselt number and Sherwood number are also presented.

Findings

The no-slip condition is considered for the present study. The effects of electromagnetohydrodynamics enhance the velocity profile while thermal radiation effects tend to raise the temperature profile. The present study depicts many interesting behaviors that warrant further study on Riga plates with different non-Newtonian fluid models. A comparison is also presented with the existing published results which confirms the validity of the presented methodology.

Originality/value

The results of this paper are new and original.

Details

Multidiscipline Modeling in Materials and Structures, vol. 12 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 18 August 2021

Manoj Kumar Nayak, Sachin Shaw, H. Waqas and Taseer Muhammad

The purpose of this study is to investigate the Cattaneo-Christov double diffusion, multiple slips and Darcy-Forchheimer’s effects on entropy optimized and thermally radiative…

Abstract

Purpose

The purpose of this study is to investigate the Cattaneo-Christov double diffusion, multiple slips and Darcy-Forchheimer’s effects on entropy optimized and thermally radiative flow, thermal and mass transport of hybrid nanoliquids past stretched cylinder subject to viscous dissipation and Arrhenius activation energy.

Design/methodology/approach

The presented flow problem consists of the flow, heat and mass transportation of hybrid nanofluids. This model is featured with Casson fluid model and Darcy-Forchheimer model. Heat and mass transportations are represented with Cattaneo-Christov double diffusion and viscous dissipation models. Multiple slip (velocity, thermal and solutal) mechanisms are adopted. Arrhenius activation energy is considered. For graphical and numerical data, the bvp4c scheme in MATLAB computational tool along with the shooting method is used.

Findings

Amplifying curvature parameter upgrades the fluid velocity while that of porosity parameter and velocity slip parameter whittles down it. Growing mixed convection parameter, curvature parameter, Forchheimer number, thermally stratified parameter intensifies fluid temperature. The rise in curvature parameter and porosity parameter enhances the solutal field distribution. Surface viscous drag gets controlled with the rising of the Casson parameter which justifies the consideration of the Casson model. Entropy generation number and Bejan number upgrades due to growth in diffusion parameter while that enfeeble with a hike in temperature difference parameter.

Originality/value

To the best of the authors’ knowledge, this research study is yet to be available in the existing literature.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 October 2019

Kasra Ayoubi Ayoubloo, Mohammad Ghalambaz, Taher Armaghani, Aminreza Noghrehabadi and Ali J. Chamkha

This paper aims to theoritically investigate the free convection flow and heat transfer of a non-Newtonian fluid with pseudoplastic behavior in a cylindrical vertical cavity…

Abstract

Purpose

This paper aims to theoritically investigate the free convection flow and heat transfer of a non-Newtonian fluid with pseudoplastic behavior in a cylindrical vertical cavity partially filled with a layer of a porous medium.

Design/methodology/approach

The non-Newtonian behavior of the pseudoplastic liquid is described by using a power-law non-Newtonian model. There is a temperature difference between the internal and external cylinders. The porous layer is attached to the internal cylinder and has a thickness of D. Upper and lower walls of the cavity are well insulated. The governing equations are transformed into a non-dimensional form to generalize the solution. The finite element method is used to solve the governing equations numerically. The results are compared with the literature results in several cases and found in good agreement.

Findings

The influence of the thickness of the porous layer, Rayleigh number and non-Newtonian index on the heat transfer behavior of a non-Newtonian pseudoplastic fluid is addressed. The increase of pseudoplastic behavior and increase of the thickness of the porous layer enhances the heat transfer. By increase of the porous layer from 0.6 to 0.8, the average Nusselt number increased from 0.15 to 0.25. The increase of non-Newtonian effects (decrease of the non-Newtonian power-law index) enhances the heat transfer rate.

Originality/value

The free convection behavior of a pseudoplastic-non-Newtonian fluid in a cylindrical enclosure partially filled by a layer of a porous medium is addressed for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 30 April 2020

Darya Loenko, Aroon Shenoy and Mikhail Sheremet

This paper aims to study the mathematical modeling of passive cooling systems for electronic devices. Improving heat transfer is facilitated by the correct choice of the working…

Abstract

Purpose

This paper aims to study the mathematical modeling of passive cooling systems for electronic devices. Improving heat transfer is facilitated by the correct choice of the working fluid and the geometric configuration of the engineering cavity; therefore, this work is devoted to the analysis of the influence of the position of the heat-generating element and the tilted angle of the electronic cabinet on the thermal convection of a non-Newtonian fluid.

Design/methodology/approach

The area of interest is a square cavity with two cold vertical walls, while the horizontal boundaries are adiabatic. An element of constant volumetric heat generation is placed on the lower wall of the chamber. The problem is described by Navier–Stokes partial differential equations using dimensionless stream function and vorticity. The numerical solution is based on the developed computational code using the finite difference technique and a uniform rectangular grid.

Findings

The key conclusions of this work are the results of a detailed analysis of streamlines and isotherms, the average Nusselt number and profiles of the average heater temperature. It was found that more intensive cooling of the heat-generating element occurs when the cavity is filled with a pseudoplastic fluid (n < 1) and not inclined (α = 0). The Rayleigh number of Ra = 105 and the thermal conductivity ratio of k = 100 are characterized by the most positive effect.

Originality/value

The originality of the research lies in both the study of thermal convection in a square chamber filled with power-law fluid under the influence of a volumetric heat production element and the analysis of the influence of geometric and thermophysical parameters characterizing the considered process.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 6 October 2023

MD. Shamshuddin, Anwar Saeed, S.R. Mishra, Ramesh Katta and Mohamed R. Eid

Whilst a modest number of investigations have been undertaken concerning nanofluids (NFs), the exploration of fluid flow under exponentially stretching velocities using NFs…

Abstract

Purpose

Whilst a modest number of investigations have been undertaken concerning nanofluids (NFs), the exploration of fluid flow under exponentially stretching velocities using NFs remains comparatively uncharted territory. This work presents a distinctive contribution through the comprehensive examination of heat and mass transfer phenomena in the NF ND–Cu/H2O under the influence of an exponentially stretching velocity. Moreover, the investigation delves into the intriguing interplay of gyrotactic microorganisms and convective boundary conditions within the system.

Design/methodology/approach

Similarity transformations have been used on PDEs to convert them into dimensionless ODEs. The solution is derived by using the homotopy analysis method (HAM). The pictorial notations have been prepared for sundry flow parameters. Furthermore, some engineering quantities are calculated in terms of the density of motile microbes, Nusselt and Sherwood numbers and skin friction, which are presented in tabular form.

Findings

The mixed convection effect associated with the combined effect of the buoyancy ratio, bioconvection Rayleigh constant and the resistivity due to the magnetization property gives rise to attenuating the velocity distribution significantly in the case of hybrid nanoliquid. The parameters involved in the profile of motile microorganisms attenuate the profile significantly.

Practical implications

The current simulations have uncovered fascinating discoveries about how metallic NFs behave near a stretched surface. These insights give us valuable information about the characteristics of the boundary layer close to the surface under exponential stretching.

Originality/value

The novelty of the current investigation is the analysis of NF ND–Cu/H2O along with an exponentially stretching velocity in a system with gyrotactic microorganisms. The investigation of fluid flow at an exponentially stretching velocity using NFs is still relatively unexplored.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 October 2016

Gholamreza Kefayati

The thermal-diffusion (Soret) and the diffusion-thermo (Dufour) effects play a crucial role in double diffusive mixed convection in a lid-driven cavity; but they have not been…

Abstract

Purpose

The thermal-diffusion (Soret) and the diffusion-thermo (Dufour) effects play a crucial role in double diffusive mixed convection in a lid-driven cavity; but they have not been studied properly by researchers. The purpose of this paper is to investigate effects of Soret and Dufour parameters on double diffusive laminar mixed convection of shear-thinning and Newtonian fluids in a two-sided lid-driven cavity.

Design/methodology/approach

Finite Difference Lattice Boltzmann method (FDLBM) has been applied to solve the complex problem. This study has been conducted for the certain pertinent parameters of Richardson number (Ri=0.00062-1), power-law index (n=0.2-1), Soret parameter (Sr=−5-5) as Dufour number effects have been investigated from Dr=−5 to 5 at Buoyancy ratio of N=1 and Lewis number of Le=5.

Findings

Results indicate that the augmentation of Richardson number causes heat and mass transfer to decrease. The fall of the power-law index declines heat and mass transfer at Ri=0.00062 and 0.01 in various Dufour and Soret parameters. At Ri=1, the heat and mass transfer rise with the increment of power-law index for Dr=0 and Sr=0. The least effect of power-law index on heat and mass transfer among the studied Richardson numbers was observed at Ri=1. The positive Dufour numbers augment the heat transfer gradually as the positive Soret numbers enhance the mass transfer. The Dr=−5 and Sr=−5 provokes the negative average Nusselt and Sherwood numbers, respectively, to be generated. The least magnitude of the average Nusselt and Sherwood numbers were obtained at Dr=−1 and Sr=−1, respectively.

Originality/value

Soret and Dufour effects in double diffusive mixed convection has not been studied in a lid-driven cavity. In addition. this study has been conducted also for shear-thinning fluids.

Details

Engineering Computations, vol. 33 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 19 February 2020

Seyyed Masoud Seyyedi, A.S. Dogonchi, M. Hashemi-Tilehnoee, D.D. Ganji and Ali J. Chamkha

Natural convection heat transfer analysis can be completed using entropy generation analysis. This study aims to accomplish both the natural convection heat transfer and entropy…

Abstract

Purpose

Natural convection heat transfer analysis can be completed using entropy generation analysis. This study aims to accomplish both the natural convection heat transfer and entropy generation analyses for a hexagonal cavity loaded with Cu-H2O nanoliquid subjected to an oriented magnetic field.

Design/methodology/approach

Control volume-based finite element method is applied to solve the non-dimensional forms of governing equations and then, the entropy generation number is computed.

Findings

The results portray that both the average Nusselt and entropy generation numbers boost with increasing aspect ratio for each value of the undulation number, while both of them decrease with increasing the undulation number for each amplitude parameter. There is a maximum value for the entropy generation number at a specified value of Hartmann number. Also, there is a minimum value for the entropy generation number at a specified value of angle of the magnetic field. When the volume fraction of nanoparticles grows, the average Nusselt number increases and the entropy generation number declines. The entropy generation number attains to a maximum value at Ha = 14 for each value of aspect ratio. The average Nusselt number ascends 2.9 per cent and entropy generation number decreases 1.3 per cent for Ha = 0 when ϕ increases from 0 to 4 per cent.

Originality/value

A hexagonal enclosure (complex geometry), which has many industrial applications, is chosen in this study. Not only the characteristics of heat transfer are investigated but also entropy generation analysis is performed in this study. The ecological coefficient of performance for enclosures is calculated, too.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

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