International Journal of Thermofluids最新文献

英文中文

Thermal and hydrodynamic analysis of MHD nanofluid flow over a permeable stretching surface in porous media: Comparative study of Fe3O4, Cu, and Ag nanofluids

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-08 DOI: 10.1016/j.ijft.2025.101055

Mahmmoud M. Syam , Mohammad Alkhedher , Muhammed I. Syam

This study investigates the dynamics of Fe

_{3}

_{4}

–water, Cu–water, and Ag–water nanofluids in the context of steady, two-dimensional, incompressible laminar magnetohydrodynamic (MHD) boundary layer flow, incorporating the effects of Forchheimer number, thermal radiation, Eckert number, magnetic field parameter, non-dimensional heat generation, and solid volume fraction of nanoparticles. A Newtonian mathematical model is developed, assuming homogeneous nanoparticle distribution, negligible Brownian motion, and thermophoresis effects. Using the operational matrix method (OMM), the model is solved numerically, and the accuracy is validated through

L_{2}

-truncation errors and boundary condition comparisons. Key findings reveal that increasing the Forchheimer number reduces velocity by up to 4.7% due to enhanced porous drag, while thermal radiation increases temperature by approximately 3.8%, enhancing heat transfer. Higher Eckert numbers elevate temperature by 5.6% due to viscous dissipation, and increasing the solid volume fraction of nanoparticles improves heat transfer efficiency by up to 9.3%. Additionally, the magnetic field suppresses velocity by up to 5.6%, indicating its potential for flow control. These results offer valuable insights into optimizing heat and mass transfer in nanofluid systems under varied thermal and physical conditions.

{"title":"Thermal and hydrodynamic analysis of MHD nanofluid flow over a permeable stretching surface in porous media: Comparative study of Fe3O4, Cu, and Ag nanofluids","authors":"Mahmmoud M. Syam , Mohammad Alkhedher , Muhammed I. Syam","doi":"10.1016/j.ijft.2025.101055","DOIUrl":"10.1016/j.ijft.2025.101055","url":null,"abstract":"<div><div>This study investigates the dynamics of Fe<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>–water, Cu–water, and Ag–water nanofluids in the context of steady, two-dimensional, incompressible laminar magnetohydrodynamic (MHD) boundary layer flow, incorporating the effects of Forchheimer number, thermal radiation, Eckert number, magnetic field parameter, non-dimensional heat generation, and solid volume fraction of nanoparticles. A Newtonian mathematical model is developed, assuming homogeneous nanoparticle distribution, negligible Brownian motion, and thermophoresis effects. Using the operational matrix method (OMM), the model is solved numerically, and the accuracy is validated through <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-truncation errors and boundary condition comparisons. Key findings reveal that increasing the Forchheimer number reduces velocity by up to 4.7% due to enhanced porous drag, while thermal radiation increases temperature by approximately 3.8%, enhancing heat transfer. Higher Eckert numbers elevate temperature by 5.6% due to viscous dissipation, and increasing the solid volume fraction of nanoparticles improves heat transfer efficiency by up to 9.3%. Additionally, the magnetic field suppresses velocity by up to 5.6%, indicating its potential for flow control. These results offer valuable insights into optimizing heat and mass transfer in nanofluid systems under varied thermal and physical conditions.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101055"},"PeriodicalIF":0.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An investigation into spray combustion processes of waste cooking oil biodiesel fuel under diesel engine conditions using the LIF-PIV, shadowgraph, and chemiluminescence techniques

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-08 DOI: 10.1016/j.ijft.2025.101066

O.A. Kuti , K. Nishida

In this study, WCO biodiesel and conventional diesel fuels were characterized fundamentally in the context of their spray, gas entrainment, and combustion characteristics under diesel-like engine conditions. This was achieved using laser-induced fluorescence and particle image velocimetry (LIF-PIV), shadowgraph, and chemiluminescence techniques under non-evaporating, evaporating, and reacting conditions. The impact of fuel injection pressure and nozzle diameter on spray and gas entrainment characteristics of the fuel were also investigated. Due to higher viscosity and surface tension, it was observed that WCO biodiesel produced longer spray penetration and narrower spray angle than diesel fuel under non-evaporating conditions. Furthermore, the quantity of gas entrained by WCO biodiesel spray was lower. Due to higher distillation temperature and less gas entrainment, the WCO biodiesel liquid length was longer. The combined effect of ultra-high injection pressure of 300 MPa with a smaller nozzle hole diameter of 0.08 mm was observed to enhance gas entrainment processes. Due to its higher cetane number, WCO biodiesel displayed a shorter ignition delay. While higher injection pressure influenced the combustion processes, with less air entrained upstream of the WCO biodiesel lifted flame, it was observed that fuel oxygen content played a crucial role in its soot formation.

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引用次数: 0

Significance of activation energy and binary chemical reaction effects on mixed convection Falkner–Skan flow of nanofluid along a wedge

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-08 DOI: 10.1016/j.ijft.2025.101070

Aamir Hamid, Zahoora Maqsood, Nafeesa Farooq

Heating profiles and reaction rates, which are crucial in the mixed convection Falkner–Skan flow of nanofluids down a wedge, are strongly influenced by the binary chemical reaction and activation energy. Slower chemical reactions caused by higher activation energy affect concentration layers and heat transmission mechanisms. Heat generation, absorption, flow, and thermal properties are all changed by binary processes. In a variety of technical and industrial applications, their combined effects are crucial in either increasing or decreasing the efficiency of heat and mass transport. The governing equations have been appropriately converted into a set of ordinary differential equations in order to handle these dynamics. The bvp4c scheme in MATLAB software has been used to solve the resulting equations. Skin friction, local Nusselt number, and velocity, temperature, and nanoparticle concentration profiles are discussed and illustrated graphically in the paper. The findings show that increasing the wedge angle parameter increases the nanofluid's velocity, whereas the Darcy number shows the opposite trend.

{"title":"Significance of activation energy and binary chemical reaction effects on mixed convection Falkner–Skan flow of nanofluid along a wedge","authors":"Aamir Hamid, Zahoora Maqsood, Nafeesa Farooq","doi":"10.1016/j.ijft.2025.101070","DOIUrl":"10.1016/j.ijft.2025.101070","url":null,"abstract":"<div><div>Heating profiles and reaction rates, which are crucial in the mixed convection Falkner–Skan flow of nanofluids down a wedge, are strongly influenced by the binary chemical reaction and activation energy. Slower chemical reactions caused by higher activation energy affect concentration layers and heat transmission mechanisms. Heat generation, absorption, flow, and thermal properties are all changed by binary processes. In a variety of technical and industrial applications, their combined effects are crucial in either increasing or decreasing the efficiency of heat and mass transport. The governing equations have been appropriately converted into a set of ordinary differential equations in order to handle these dynamics. The bvp4c scheme in MATLAB software has been used to solve the resulting equations. Skin friction, local Nusselt number, and velocity, temperature, and nanoparticle concentration profiles are discussed and illustrated graphically in the paper. The findings show that increasing the wedge angle parameter increases the nanofluid's velocity, whereas the Darcy number shows the opposite trend.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101070"},"PeriodicalIF":0.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Neural networking analysis of thermally magnetized mass transfer coefficient (MTC) for Carreau fluid flow: A comparative study

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-08 DOI: 10.1016/j.ijft.2025.101069

Khalil Ur Rehman , Wasfi Shatanawi , Zeeshan Asghar , A.R.M. Kasim

The non-Newtonian fluids are used in several operations, including the transportation of crude oil, drilling fluids, and hydraulic fracturing fluids. These fluids' flow characteristics can be described by the Carreau model, which helps with the planning and improvement of manufacturing and transportation procedures. Owing to such motivation we have considered the Carreau fluid flow subject to a magnetized flat surface with porosity, heat generation, temperature slip, chemical reaction, and velocity slip effects. The problem is formulated as coupled differential equations. For solution purposes, the order of equations is reduced by performing Lie symmetry analysis. The compact equations are further solved by the shooting method. The evaluation of the mass transfer coefficient for the Carreau fluid model is done by using an Artificial Intelligence based neural model. The Schmidt number, porosity, magnetic, Weissenberg number, and chemical reaction parameters are treated as inputs while the mass transfer rate is taken as output. Owing to 10 neurons in the hidden layer, the network is trained by the Levenberg-Marquardt algorithm. It is found that the mass transfer rate exhibits a direct relation with the Schmidt number and chemical reaction parameter. The magnitude of the Carreau concentration is perceived to be higher for non-porous surfaces when the chemical reaction parameter and Schmidt number exhibit positive change.

{"title":"Neural networking analysis of thermally magnetized mass transfer coefficient (MTC) for Carreau fluid flow: A comparative study","authors":"Khalil Ur Rehman , Wasfi Shatanawi , Zeeshan Asghar , A.R.M. Kasim","doi":"10.1016/j.ijft.2025.101069","DOIUrl":"10.1016/j.ijft.2025.101069","url":null,"abstract":"<div><div>The non-Newtonian fluids are used in several operations, including the transportation of crude oil, drilling fluids, and hydraulic fracturing fluids. These fluids' flow characteristics can be described by the Carreau model, which helps with the planning and improvement of manufacturing and transportation procedures. Owing to such motivation we have considered the Carreau fluid flow subject to a magnetized flat surface with porosity, heat generation, temperature slip, chemical reaction, and velocity slip effects. The problem is formulated as coupled differential equations. For solution purposes, the order of equations is reduced by performing Lie symmetry analysis. The compact equations are further solved by the shooting method. The evaluation of the mass transfer coefficient for the Carreau fluid model is done by using an Artificial Intelligence based neural model. The Schmidt number, porosity, magnetic, Weissenberg number, and chemical reaction parameters are treated as inputs while the mass transfer rate is taken as output. Owing to 10 neurons in the hidden layer, the network is trained by the Levenberg-Marquardt algorithm. It is found that the mass transfer rate exhibits a direct relation with the Schmidt number and chemical reaction parameter. The magnitude of the Carreau concentration is perceived to be higher for non-porous surfaces when the chemical reaction parameter and Schmidt number exhibit positive change.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101069"},"PeriodicalIF":0.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

MHD darcy-forchheimer flow of SWCNT-H2O nanofluid over a porous stretching sheet

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-06 DOI: 10.1016/j.ijft.2025.101064

Suresh Kumar , Sushila Choudhary , Kiran Kumari , Anil Sharma , Prasun Choudhary

Single walled carbon nanotubes exhibit unique electronic properties that make them ideal for miniaturizing electronics and serving as excellent conductors in various nanotechnological applications. The aim of this numerical simulation of water-based single-walled carbon nanotube (SWCNT) nanofluid flow over a vertical porous sheet is to study the flow and heat transfer characteristics of this nanofluid through a non-darcy permeable medium. Other flow controlling conditions, like viscous dissipation and a uniform magnetic field, are also included during this study. The current analysis is an innovative in terms of stagnation point flow for the described fluid system in the presence of Darcy-Forchheimer effect, Joule heating, and non-uniform heat generation/absorption impact. A mathematical framework is established using partial differential equations to depict the flow and temperature processes, using appropriate boundary conditions. We transformed the mathematical framework into dimensionless form using similarity parameters and subsequently solved it with Bvp4c MATLAB code. Numerical outcomes are presented via graphs and tables. When the velocity ratio parameter exceeds 1, the velocity profile decreases with increasing magnetic parameter due to the enhanced Lorentz force that opposes the fluid motion. Both fluid velocity and temperature profiles increase with rising mixed convection parameter and nanotube volume fraction due to enhanced buoyancy and convective effects.

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引用次数: 0

Numerical optimization of water tube boiler energy recovery using a new economizer

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-06 DOI: 10.1016/j.ijft.2025.101061

Abbas Behzadi , Ali Akbar Abbasian Arani , Ali Arefmanesh

The aim of this research is to recommend a numerical model for investigation on the flue gases heat recovery economizer. Due to fulfill of this request, the effects of the presence of ash on the pipes and sediment inside the pipe features and optimization of a complex heat exchanger (3D) equipped with bare and finned tubes are studied. In this work, the effects of distance between the tubes have been investigated. Based on obtained results, for the economizer equipped with finned tubes, determination of optimal tube pitch to have more boiler efficiency is essential. After installing the economizer, the boiler performance test is performed so that the simulation results are validated and verified in practice. When the economizer operated at 70% working load, equipping with an economizer will save 9,500 tons of gas fuel and for five steam boilers, the gas fuel will be reduced by 47 thousand tons at one year. In conclusion, the arrangement with outer helical fins having di =43.8 mm, do = 50.8mm, t = 1.3 mm, l=4900 mm with 2.75*7*4.54 m economizer are studied with different tube distances, and SL=150 mm is presented as the optimal model with the highest performance between all configurations.

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引用次数: 0

Numerical study of the porous medium effects on mixed convective Fe3O4 − water ferrofluid flow in an annular region between heated inner cylinder and outer melting ice wall

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-06 DOI: 10.1016/j.ijft.2025.101062

Stephon De Souze, Victor Job, Mahesha Narayana

In this study, the mixed convection of Fe₃O₄ − water ferrofluid in an infinitely long vertical annulus with a heated inner cylinder and surrounding regions of aluminium metal foam, free fluid and ice was conducted. The scope of this study entails investigating the effects of porous medium properties on the heat transfer from the inner cylinder to the ferrofluid and melting of the outer cylindrical ice wall. This was achieved by using the Brinkman-Forchheimer model to describe the ferrofluid flow through the porous region and the Navier-Stokes equations in the free flow region. To solve the system of nonlinear partial differential equations, the finite element method along with the Crank-Nicholson scheme was used and results were simulated graphically. Results show that an increase in the permeability of the porous medium causes a 40.4 % (from Da = 1 × 10⁻⁵ to Da = 5 × 10⁻³) increase the velocity of ferrofluid, but has no significant effect on the melting of ice (0.2 % difference) and the heat transfer (0.4 % difference) from inner cylinder to the fluid. Although an increase in the thickness of the porous medium region does not affect the melting of ice (<1.5 % relative change in ice thickness), it significantly increases the heat transfer from the inner cylinder to the fluid by at most 16.0 % and reduces the magnitude of the velocity of the ferrofluid by a maximum of 82.5 %. This study has applications in fields such as electrical engineering, specifically for delivery of current in cold environments.

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引用次数: 0

A novel computational approach for electro-osmosis flow: A compact scheme perspective

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-05 DOI: 10.1016/j.ijft.2025.101054

Muhammad Shoaib Arif , Ateeq Ur Rehman , Yasir Nawaz

Applications such as microfluidic systems, medication administration, and soil stability greatly benefit from electro-osmosis, which describes fluid movement generated by an electric field within a charged media. Specifically for time-dependent partial differential equations (PDEs) describing electro-osmosis flow in Newtonian fluids with rescaled viscosity, this research suggests a new two-stage computational method. The proposed approach uses a second-order Runge–Kutta technique in the second stage and an exponential-type integrator in the first stage of its two explicit stages. Using a compact finite difference approach, spatial discretization can be accomplished with minimal grid points while achieving excellent accuracy. The scheme is guaranteed to be stable across various PDE models by providing stability analyses for scalar convection-diffusion problems and convergence analyses for systems of convection-diffusion equations. The dynamics of electro-osmosis flow are modeled using a dimensionless version of the governing equations. By comparing it to the Euler and conventional Runge–Kutta methods, we find that the suggested scheme is more stable and accurate, making it a great candidate for computational fluid dynamics.

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引用次数: 0

Supersonic flow control with quarter rib in a duct: An extensive CFD study

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-04 DOI: 10.1016/j.ijft.2025.101060

Ambareen Khan , Abdul Aabid , Mohammad Nishat Akhtar , Sher Afghan Khan , Muneer Baig

A sudden increase in the area of a duct or at the blunt base of the projectile leads to flow separation and reattachment. In the flow separation process, the base pressure at the blunt base is sub-atmospheric, leading to significant drag, which can be around sixty to seventy percent. This study is undertaken to regulate the base pressure in the recirculation zone and the flow field of the duct. This paper focuses on the effectiveness of quarter ribs of various radii in the range from 1 mm to mm and nozzle pressure ratio ranging from 3 to 11 at Mach M = 1.48 for a duct diameter of 22 mm and its sizes ranging from 1D to 6D. Some oscillations are observed for the rib location of 11 mm from the exit of the nozzle. Due to the proximity to the nozzle exit, these oscillations are observed. With a progressive shift of passive control along the more significant length, a continued rise in the pressure in the base region for rib radii in the range from 2 mm to 4 mm and an extreme increase in the base pressure is achieved for 4 mm rib radii placed at 66 mm inside the duct. Nevertheless, despite the maximum enhancement in pressure for duct size L = 4D, a negligible reduction in base pressure and ambient pressure cannot affect the flow contained by the duct for a more considerable duct length. However, using a quarter rib radii of 1mm is inadequate, and base pressure values are identical with and without rib except for the nozzle pressure ratio (NPR) = 3, where the nozzle at NPR = 3 is over-expanded. Except at NPR = 3, the nozzles are under-expanded, and the control mechanism becomes efficient, resulting in a significant base pressure increase. One can make a final decision based on the mission requirements about the radius of the rib, rib location, and level of expansion to meet the user's requirements.

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引用次数: 0

Impact of micropolar effects on nanofluid flow between two disks

Q1 Chemical Engineering

International Journal of Thermofluids

Pub Date : 2025-01-03 DOI: 10.1016/j.ijft.2024.101050

S. Saranya , P. Ragupathi , Qasem M. Al-Mdallal

This paper investigates how ester-based nanofluids flow between two parallel disks when subjected to micropolar effects. Compared to traditional Newtonian fluids, micropolar fluids which exhibit spin inertia and micro-rotation provide a more thorough knowledge of the behaviour of complicated fluids. The ester-based nanofluid, selected due to its exceptional thermal characteristics and favourable environmental effects, is examined with different micropolar parameters to evaluate their impact on heat transfer rates and flow dynamics. Initially, we created a mathematical model to explain the fluid dynamics of ester-based micropolar nanofluids between two parallel disks using the Navier-Stokes equations. The suggested mathematical problem is converted into a non-linear ordinary differential equation (ODE) using the similarity transformation technique. We then solved the governing equations numerically using MATLAB's built-in BVP4c method. Through numerical simulations, we explored the velocity distribution, micro-rotation profiles and temperature profiles within the disk system. The results reveal that micropolar effects significantly enhance the thermal conductivity and viscosity of the nanofluid, leading to improved heat transfer efficiency and altered flow patterns. Nanoparticles in porous disk flow increase velocity and micro-rotation profiles, resulting in a more streamlined flow. Nanoparticle volume fraction also increases temperature, reducing thermal boundary layer thickness and enhancing convective heat transfer.

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引用次数: 0

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