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Article
Publication date: 5 April 2021

Ali Akbar Abbasian Arani and Hamed Uosofvand

This paper aims to present a numerical investigation on laboratory-scale segmental baffles shell-and-tube heat exchanger (STHX) having various tube bundles and baffle…

Abstract

Purpose

This paper aims to present a numerical investigation on laboratory-scale segmental baffles shell-and-tube heat exchanger (STHX) having various tube bundles and baffle configuration.

Design/methodology/approach

To discover the higher performance the thermohydraulic behavior of shell-side fluid flow with circular, elliptical and twisted oval tube bundles with segmental and inclined segmental baffled is compared. Shell side turbulent flow and heat transfer are simulated by a finite volume discretization approach using SolidWorks Flow Simulation. To achieve greater configuration performance of this device, the following two approaches is considered: using the inclined baffle with 200 angles of inclination and applying the different tube bundle.

Findings

Different parameters as heat transfer rate, pressure drop (Δp), heat transfer coefficient (h) and heat transfer coefficient to pressure drop ratio (h/Δp) are presented and discussed. Besides, for considering the effect of pressure penalty and heat transfer improvement instantaneously, the efficiency evaluation coefficient (EEC) in the fluid flow and heat transfer based on the power required to provide the real heat transfer augmentation are used.

Originality/value

Obtained results displayed that, at the equal mass flow rate, the twisted oval tubes with segmental baffle decrease the pressure drop 53.6% and 35.64% rather than that the circular and elliptical tubes bundle, respectively. By comparing the (h/Δp) ratio, it can result that the STHX with twisted oval tubes bundle (both segmental and inclined baffle) has better performance than other kinds of the tube bundles. Present results showed that the values of the EEC for all provided models are higher than 1, except for elliptical tube bundles with segmental baffles. The STHX with twisted oval tube bundles and segmental baffle gives the highest EEC value equal to 1.16 in the range of investigated mass flow.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 12
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 25 June 2019

Seyed Mohammad Mousavi, Omid Ali Akbari, Ghanbarali Sheikhzadeh, Ali Marzban, Davood Toghraie and Ali J. Chamkha

The purpose of this study is two phase modeling of Water/Cu nanofluid forced convection in different arrangements of elliptical tube banks in a two-dimensional space.

Abstract

Purpose

The purpose of this study is two phase modeling of Water/Cu nanofluid forced convection in different arrangements of elliptical tube banks in a two-dimensional space.

Design/methodology/approach

The arrangements of tube banks have been regarded as equal spacing triangle (ES), equilateral triangle (ET) and the rotated square (RS). The obtained results indicate that, among the investigated arrangements, the RS arrangement has the maximum value of heat transfer with cooling fluid. Also, the changes of Nusselt number and the local friction factor are under the influence of three main factors including volume fraction of slid nanoparticles, the changes of fluid velocity parameters on the curved surface of tube and flow separation after crossing from a specified angle of fluid rotation.

Findings

In Reynolds number of 250 and in all arrangements of the tube banks, the behavior of Nusselt number is almost the same and the separation of flow happens in almost 155-165 degrees from fluid rotation on surface. In RS arrangement, due to the strength of vortexes after fluid separation, better mixture is created and because of this reason, after the separation zone, the level of local Nusselt number graph enhances significantly.

Originality/value

In this research, the laminar and two-phase flow of Water/Cu nanofluid in tube banks with elliptical cross section has been numerically investigated in a two-dimensional space with different longitudinal arrangements. In this study, the effects of using nanofluid, different arrangements of tube banks and the elliptical cross section on heat transfer and cooling fluid flow among the tube banks of heat exchanger have been numerically simulated by using finite volume method.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 25 March 2024

Emrehan Gürsoy, Hayati Kadir Pazarlioğlu, Mehmet Gürdal, Engin Gedik, Kamil Arslan and Abdullah Dağdeviren

The purpose of this study is to analyse the magnetic field effect on Fe3O4/H2O Ferrofluid flowing in a sudden expansion tube, which has specific behaviour in terms of rheology…

Abstract

Purpose

The purpose of this study is to analyse the magnetic field effect on Fe3O4/H2O Ferrofluid flowing in a sudden expansion tube, which has specific behaviour in terms of rheology, with convex dimple fins. Because the investigation of flow separation is a prominent application in performance, the effect of magnetic field and convex dimple on the thermo-hydraulic performance of sudden expansion tube are examined, in detail.

Design/methodology/approach

During the solution of the boundary conditions of the sudden expansion tube, finite volume method was used. Analyses have been conducted considering the single-phase solution, steady-state, incompressible fluid and no-slip condition of the wall under forced convection conditions. In the analyses, it has been assumed that the flow was developing thermally and has been fully developed hydrodynamically.

Findings

The present study focuses on exploring the influence of the magnetic field, nanofluid concentration and convex dimple fins on the thermo-hydraulic performance of sudden expansion tube. The results indicate that the strength of the magnetic field, nanofluid concentration and convex dimple fins have a positive effect on the convective heat transfer in the system.

Originality/value

The authors conducted numerical studies, determining through a literature search that no one had yet investigated enhancing heat transfer on a sudden expansion tube using combinations of magnetic fields, nanofluids and convex dimple fins. The results of the numerical analyses provide valuable information about the improvement of heat transfer and system performance in electronic device cooling and heat exchangers.

Details

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

Keywords

Article
Publication date: 12 October 2018

Haroun Ragueb and Kacem Mansouri

The purpose of this study is to investigate the thermal response of the laminar non-Newtonian fluid flow in elliptical duct subjected to a third-kind boundary condition with a…

Abstract

Purpose

The purpose of this study is to investigate the thermal response of the laminar non-Newtonian fluid flow in elliptical duct subjected to a third-kind boundary condition with a particular interest to a non-Newtonian nanofluid case. The effects of Biot number, aspect ratio and fluid flow behavior index on the heat transfer have been examined carefully.

Design/methodology/approach

First, the mathematical problem has been formulated in dimensionless form, and then the curvilinear elliptical coordinates transform is applied to transform the original elliptical shape of the duct to an equivalent rectangular numerical domain. This transformation has been adopted to overcome the inherent mathematical deficiency due to the dependence of the ellipsis contour on the variables x and y. The yielded problem has been successfully solved using the dynamic alternating direction implicit method. With the available temperature field, several parameters have been computed for the analysis purpose such as bulk temperature, Nusselt number and heat transfer coefficient.

Findings

The results showed that the use of elliptical duct enhances significantly the heat transfer coefficient and reduces the duct’s length needed to achieve the thermal equilibrium. For some cases, the reduction in the duct’s length can reach almost 50 per cent compared to the circular pipe. In addition, the analysis of the non-Newtonian nanofluid case showed that the addition of nanoparticles to the base fluid improves the heat transfer coefficient up to 25 per cent. The combination of using an elliptical duct and the addition of nanoparticles has a spectacular effect on the overall heat transfer coefficient with an enhancement of 50-70 per cent. From the engineering applications view, the results demonstrate the potential of elliptical duct in building light-weighted compact shell-and-tube heat exchangers.

Originality/value

A complete investigation of the heat transfer of a fully developed laminar flow of power law fluids in elliptical ducts subject to the convective boundary condition with application to non-Newtonian nanofluids is addressed.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Open Access
Article
Publication date: 24 October 2022

Babak Lotfi and Bengt Ake Sunden

This study aims to computational numerical simulations to clarify and explore the influences of periodic cellular lattice (PCL) morphological parameters – such as lattice…

1131

Abstract

Purpose

This study aims to computational numerical simulations to clarify and explore the influences of periodic cellular lattice (PCL) morphological parameters – such as lattice structure topology (simple cubic, body-centered cubic, z-reinforced body-centered cubic [BCCZ], face-centered cubic and z-reinforced face-centered cubic [FCCZ] lattice structures) and porosity value ( ) – on the thermal-hydraulic characteristics of the novel trussed fin-and-elliptical tube heat exchanger (FETHX), which has led to a deeper understanding of the superior heat transfer enhancement ability of the PCL structure.

Design/methodology/approach

A three-dimensional computational fluid dynamics (CFD) model is proposed in this paper to provide better understanding of the fluid flow and heat transfer behavior of the PCL structures in the trussed FETHXs associated with different structure topologies and high-porosities. The flow governing equations of the trussed FETHX are solved by the CFD software ANSYS CFX® and use the Menter SST turbulence model to accurately predict flow characteristics in the fluid flow region.

Findings

The thermal-hydraulic performance benchmarks analysis – such as field synergy performance and performance evaluation criteria – conducted during this research successfully identified demonstrates that if the high porosity of all PCL structures decrease to 92%, the best thermal-hydraulic performance is provided. Overall, according to the obtained outcomes, the trussed FETHX with the advantages of using BCCZ lattice structure at 92% porosity presents good thermal-hydraulic performance enhancement among all the investigated PCL structures.

Originality/value

To the best of the authors’ knowledge, this paper is one of the first in the literature that provides thorough thermal-hydraulic characteristics of a novel trussed FETHX with high-porosity PCL structures.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 7 November 2016

Babak Lotfi, Bengt Sunden and Qiu-Wang Wang

The purpose of this paper is to investigate the numerical fluid-structure interaction (FSI) framework for the simulations of mechanical behavior of new vortex generators (VGs) in…

412

Abstract

Purpose

The purpose of this paper is to investigate the numerical fluid-structure interaction (FSI) framework for the simulations of mechanical behavior of new vortex generators (VGs) in smooth wavy fin-and-elliptical tube (SWFET) heat exchanger using the ANSYS MFX Multi-field® solver.

Design/methodology/approach

A three-dimensional FSI approach is proposed in this paper to provide better understanding of the performance of the VG structures in SWFET heat exchangers associated with the alloy material properties and geometric factors. The Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model are applied for modeling of the turbulent flow in SWFET heat exchanger and the linear elastic Cauchy-Navier model is solved for the structural von Mises stress and elastic strain analysis in the VGs region.

Findings

Parametric studies conducted in the course of this research successfully identified illustrate that the maximum magnitude of von Mises stress and elastic strain occurs at the root of the VGs and depends on geometrical parameters and material types. These results reveal that the titanium alloy VGs shows a slightly higher strength and lower elastic strain compared to the aluminum alloy VGs.

Originality/value

This paper is one of the first in the literature that provides original information mechanical behavior of a SWFET heat exchanger model with new VGs in the field of FSI coupling technique.

Article
Publication date: 30 May 2008

Q.W. Wang, D.J. Zhang, M. Zeng, M. Lin and L.H. Tang

The purpose of this paper is to investigate the overall flow and temperature field of the air in the whole power plant, especially around the air‐cooled heat exchanger (ACHE) to…

3545

Abstract

Purpose

The purpose of this paper is to investigate the overall flow and temperature field of the air in the whole power plant, especially around the air‐cooled heat exchanger (ACHE) to evaluate the feasibility of the thermal plant project.

Design/methodology/approach

The commercial computational fluid dynamics code FLUENT with standard kε turbulent model was used. The buoyancy of the air was also considered.

Findings

It is concluded that plume recirculation occurs in each case due to the wind effect and the suction of the fan. Installing a side board below or above the fan platform (side board I or side board II) is an effective method of avoiding the plume recirculation and, the higher the board, the better the effect. When the height of the side board I H1≥10 m or the height of the side board II H2≥12 m, the temperature distributions of the fan platform will be sufficient to meet the requirement.

Research limitations/implications

A proper distance between the adjacent high buildings and the ACHE should be found with further investigation.

Practical implications

The paper presents a very useful numerical method for the prediction of the flow and temperature field around ACHE or in a large space.

Originality/value

The paper provides the numerical simulation of the flow and heat transfer inside the whole thermal power plant. Suggestions which can effectively avoid the unfavorable influence and ensure the whole system in safe conditions are offered. The study gives some useful information to the design of a thermal power plant with an ACHE system.

Details

Engineering Computations, vol. 25 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 December 1997

Fausto A.A. Barbuto and Renato Machado Cotta

Employs the integral transform method in the hybrid numerical‐analytical solution of fully developed laminar flow within a class of irregularly shaped ducts, with respect to the…

Abstract

Employs the integral transform method in the hybrid numerical‐analytical solution of fully developed laminar flow within a class of irregularly shaped ducts, with respect to the co‐ordinate system chosen to represent the geometry under consideration. A quite general formulation of a two‐dimensional steady‐state diffusion problem is initially considered, and a formal solution is provided. The original partial differential equation is analytically transformed into an infinite system of ordinary differential equations for the transformed velocity field in the flow direction. On truncation to a sufficiently large finite order, adaptively chosen to meet prescribed accuracy requirements, well‐established numerical schemes for boundary value problems are utilized, readily available in scientific subroutines libraries. Illustrates convergence rates for a few typical duct geometries and critically examines previously reported numerical solutions.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 7 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 5 January 2024

Fateh Mebarek-Oudina, Ines Chabani, Hanumesh Vaidya and Abdul Aziz I. Ismail

This paper aims to present a numerical study that investigates the flow of MgO-Al2O3/water hybrid nanofluid inside a porous elliptical-shaped cavity, in which we aim to examine…

Abstract

Purpose

This paper aims to present a numerical study that investigates the flow of MgO-Al2O3/water hybrid nanofluid inside a porous elliptical-shaped cavity, in which we aim to examine the performance of this thermal system when exposed to a magnetic field via heat transfer features and entropy generation.

Design/methodology/approach

The configuration consists of the hybrid nanofluid out layered by a cold ellipse while it surrounds a non-square heated obstacle; the thermal structure is under the influence of a horizontal magnetic field. This problem is implemented in COMSOL multiphysics, which solves the related equations described by the “Darcy-Forchheimer-Brinkman” model through the finite element method.

Findings

The results illustrated as streamlines, isotherms and average Nusselt number, along with the entropy production, are given as functions of: the volume fraction, and shape factor to assess the behaviour of the properties of the nanoparticles. Darcy number and porosity to designate the impact of the porous features of the enclosure, and finally the strength of the magnetic induction described as Hartmann number. The outcomes show the increased pattern of the thermal and dynamical behaviour of the hybrid nanofluid when augmenting the concentration, shape factor, porosity and Darcy number; however, it also engenders increased formations of irreversibilities in the system that were revealed to enhance with the permeability and the great properties of the nanofluid. Nevertheless, this thermal enhanced pattern is shown to degrade with strong Hartmann values, which also reduced both thermal and viscous entropies. Therefore, it is advised to minimize the magnetic influence to promote better heat exchange.

Originality/value

The investigation of irreversibilities in nanofluids heat transfer is an important topic of research with practical implications for the design and optimization of heat transfer systems. The study’s findings can help improve the performance and efficiency of these systems, as well as contribute to the development of sustainable energy technologies. The study also offers an intriguing approach that evaluates entropy growth in this unusual configuration with several parameters, which has the potential to transform our understanding of complicated fluid dynamics and thermodynamic processes, and at the end obtain the best thermal configuration possible.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 September 1970

Accles & Pollock Ltd. of Oldbury, Worcestershire, a TI Steel Tube Division company, will be exhibiting a comprehensive range of precision steel tube and tubular products…

Abstract

Accles & Pollock Ltd. of Oldbury, Worcestershire, a TI Steel Tube Division company, will be exhibiting a comprehensive range of precision steel tube and tubular products, including plain, annularly convoluted and thin wall tube, at Farnborough.

Details

Aircraft Engineering and Aerospace Technology, vol. 42 no. 9
Type: Research Article
ISSN: 0002-2667

1 – 10 of 566