Tri-hybrid nanofluids are formed by involving three different types of nanoparticles in the base fluid. In recent years, studies have been done to properly understand the factors that affect the heat transfer properties of these tri-hybrid nanofluids under various circumstances. The purpose of this study is to execute a study on an advanced tri-hybrid nanofluid model for heat transfer. No previous analysis has been executed for the flow of tri-hybrid nanofluid TiO2–Al2O3–SiO2/H2O past a variably thickened stretching sheet with the inclusion of Newtonian heating, magnetic field, mixed convection, thermal radiation, and viscous dissipation. This investigation confronts the heat transfer characteristics of boundary layer mixed convective flow of TiO2–Al2O3–SiO2/H2O tri-hybrid nanofluid on a variably thickened stretching sheet along with the inclusion of thermal radiation, viscous dissipation, and Newtonian heating. The ruling boundary layer equations are manipulated into an arrangement of ODEs using appropriate similarity transformations which are worked out with the bvp4c program in MATLAB for solutions. The plots obtained reveal that the variation in the non-dimensional discrete parameters induced in the investigation significantly affects the flow inside the boundary layer. The variation in Cfx and Nux are presented via 3D graphs. The reason for picking the tri-hybrid nanoparticles TiO2, Al2O3, and SiO2 is the raise in thermal conductivity with the addition of Al2O3 in comparison with low thermal conductivity values of SiO2 and TiO2 combination. This study reports that the Newtonian heating at the surface of the sheet assists the flow of tri-hybrid nanofluid TiO2–Al2O3–SiO2/H2O and conducts heat at a better rate. Also, the temperature profile of the tri-hybrid nanofluid TiO2–Al2O3–SiO2/H2O is more prominent than the plots of hybrid nanofluid TiO2–Al2O3/H2O, nanofluid TiO2/H2O, and fluid H2O.
{"title":"Mixed Convective Flow of Tri-Hybrid Nanofluid TiO2–Al2O3–SiO2/H2O Past a Variably Thicked Stretching Sheet with Newtonian Heating","authors":"Archie Thakur, Shilpa Sood, Diksha Sharma","doi":"10.1166/jon.2023.2064","DOIUrl":"https://doi.org/10.1166/jon.2023.2064","url":null,"abstract":"Tri-hybrid nanofluids are formed by involving three different types of nanoparticles in the base fluid. In recent years, studies have been done to properly understand the factors that affect the heat transfer properties of these tri-hybrid nanofluids under various circumstances. The purpose of this study is to execute a study on an advanced tri-hybrid nanofluid model for heat transfer. No previous analysis has been executed for the flow of tri-hybrid nanofluid TiO2–Al2O3–SiO2/H2O past a variably thickened stretching sheet with the inclusion of Newtonian heating, magnetic field, mixed convection, thermal radiation, and viscous dissipation. This investigation confronts the heat transfer characteristics of boundary layer mixed convective flow of TiO2–Al2O3–SiO2/H2O tri-hybrid nanofluid on a variably thickened stretching sheet along with the inclusion of thermal radiation, viscous dissipation, and Newtonian heating. The ruling boundary layer equations are manipulated into an arrangement of ODEs using appropriate similarity transformations which are worked out with the bvp4c program in MATLAB for solutions. The plots obtained reveal that the variation in the non-dimensional discrete parameters induced in the investigation significantly affects the flow inside the boundary layer. The variation in Cfx and Nux are presented via 3D graphs. The reason for picking the tri-hybrid nanoparticles TiO2, Al2O3, and SiO2 is the raise in thermal conductivity with the addition of Al2O3 in comparison with low thermal conductivity values of SiO2 and TiO2 combination. This study reports that the Newtonian heating at the surface of the sheet assists the flow of tri-hybrid nanofluid TiO2–Al2O3–SiO2/H2O and conducts heat at a better rate. Also, the temperature profile of the tri-hybrid nanofluid TiO2–Al2O3–SiO2/H2O is more prominent than the plots of hybrid nanofluid TiO2–Al2O3/H2O, nanofluid TiO2/H2O, and fluid H2O.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"15 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139330689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have examined the effect of entropy generation and nonlinear thermal radiation on magnetohydrodynamic (MHD) in Jeffrey nanofluid over a permeable stretching sheet with viscous-Ohmic dissipation and non-uniform heat source/sink. Brownian motion and thermophoresis effects have also been taken into account. The basic governing equations of the boundary layer flow are then solved numerically by the Spectral Quasilinearization method (SQLM). Various controlling physical parameters effects on velocity, temperature, concentration, entropy generation and Bejan number profiles are presented graphically. Results show that increasing the magnetic parameter, Brownian motion parameter, and thermophoresis parameter enhance the temperature profiles. Furthermore, the entropy generation profiles increase with space-dependent and temperature-dependent parameters, wall mass flux parameter, and chemical reaction parameter near to the sheet. In contrast, reverse trends are observed away from the sheet. Novelty of entropy generation is also provided to reflect the effects of several relevant physical parameters on the entropy generation rate and Bejan number.
{"title":"Analysis of Entropy Generation on MHD Radiative Viscous-Ohmic Dissipative Heat Transfer Over a Stretching Sheet in a Chemically Reactive Jeffrey Nanofluid with Non-Uniform Heat Source/Sink Based on SQLM","authors":"D. Pal, S. Mondal","doi":"10.1166/jon.2023.2096","DOIUrl":"https://doi.org/10.1166/jon.2023.2096","url":null,"abstract":"We have examined the effect of entropy generation and nonlinear thermal radiation on magnetohydrodynamic (MHD) in Jeffrey nanofluid over a permeable stretching sheet with viscous-Ohmic dissipation and non-uniform heat source/sink. Brownian motion and thermophoresis effects have also been taken into account. The basic governing equations of the boundary layer flow are then solved numerically by the Spectral Quasilinearization method (SQLM). Various controlling physical parameters effects on velocity, temperature, concentration, entropy generation and Bejan number profiles are presented graphically. Results show that increasing the magnetic parameter, Brownian motion parameter, and thermophoresis parameter enhance the temperature profiles. Furthermore, the entropy generation profiles increase with space-dependent and temperature-dependent parameters, wall mass flux parameter, and chemical reaction parameter near to the sheet. In contrast, reverse trends are observed away from the sheet. Novelty of entropy generation is also provided to reflect the effects of several relevant physical parameters on the entropy generation rate and Bejan number.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"23 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139330876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we emphasise the heat transfer and fluid flow due to buoyancy force in a wavy open porous cavity, placed horizontally having filled with porous media and, its top wall is being kept open, whereas the right cold wall is wavy and, its left vertical wall is heated partially, keeping all other walls at thermally insulated. The non-dimensional ψ − θ formulation of mass, momentum, and energy conservation laws for porous media are solved by the standard finite difference scheme for a wide range of pertinent parameters such as nanoparticle volume fraction (0.05 ≤ Φ ≤ 0.2), Rayleigh-Darcy number (10 ≤ Ra ≤ 103), length of heat source (0.25 ≤ ε ≤ 1), and parameters controlling waviness of right wall (1 ≤ N ≤ 5) and amplitude (0.05 ≤ a ≤ 0.25). The simulated results are presented in the form of streamlines and isotherms; global and local Nusselt numbers are computed. Obtained results are analyzed and it is observed that the convection process is augmented at the presence of nanoparticle for low Ra but decreases at high Ra for all pertinent parameters; also, the wall waviness augments convection low Ra.
在这项工作中，我们强调在一个水平放置、充满多孔介质的波浪形开放多孔空腔中，由于浮力而产生的传热和流体流动，其顶壁保持开放，而右侧冷壁呈波浪形，其左侧垂直壁部分加热，所有其他壁保持隔热。多孔介质的质量、动量和能量守恒定律的非维度 ψ - θ 公式是通过标准有限差分方案求解的，适用于各种相关参数，如纳米粒子体积分数（0.05 ≤ Φ ≤ 0.2）、瑞利-达西数（10 ≤ Ra ≤ 103）、热源长度（0.25 ≤ ε ≤ 1）以及控制右壁波浪度（1 ≤ N ≤ 5）和振幅（0.05 ≤ a ≤ 0.25）的参数。 模拟结果以流线和等温线的形式呈现；计算了全局和局部的努塞尔特数。对得到的结果进行分析后发现，在所有相关参数下，当纳米粒子存在时，对流过程在低 Ra 时会增强，但在高 Ra 时会减弱；此外，壁面波浪度在低 Ra 时也会增强对流。
{"title":"Numerical Computation of Natural Convection of Nanofluid in an Open Wavy Porous Cavity Heated Partially","authors":"Prabir Barman, P. Rao, Sandip Chowdhury","doi":"10.1166/jon.2023.2050","DOIUrl":"https://doi.org/10.1166/jon.2023.2050","url":null,"abstract":"In this work, we emphasise the heat transfer and fluid flow due to buoyancy force in a wavy open porous cavity, placed horizontally having filled with porous media and, its top wall is being kept open, whereas the right cold wall is wavy and, its left vertical wall is heated partially, keeping all other walls at thermally insulated. The non-dimensional ψ − θ formulation of mass, momentum, and energy conservation laws for porous media are solved by the standard finite difference scheme for a wide range of pertinent parameters such as nanoparticle volume fraction (0.05 ≤ Φ ≤ 0.2), Rayleigh-Darcy number (10 ≤ Ra ≤ 103), length of heat source (0.25 ≤ ε ≤ 1), and parameters controlling waviness of right wall (1 ≤ N ≤ 5) and amplitude (0.05 ≤ a ≤ 0.25). The simulated results are presented in the form of streamlines and isotherms; global and local Nusselt numbers are computed. Obtained results are analyzed and it is observed that the convection process is augmented at the presence of nanoparticle for low Ra but decreases at high Ra for all pertinent parameters; also, the wall waviness augments convection low Ra.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"71 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139331063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The phenomena of turbulent forced convection were investigated in a cross-shaped enclosure with an (Al2O3-Cu)/water hybrid nano-fluid. This design aims to solve the problem of overheating concentrated solar panels due to crossed solar cells in semiarid climates. The cavity’s upper horizontal and left vertical walls are kept at high temperatures, while the lower flat and suitable vertical walls are considered adiabatic. The cavity contains two inlets and one outlet. Using the finite element method, we solved the equations that controlled our situation and defined the expected turbulent flow regime for Reynolds values between 4000 and 20000. Additionally, the effects of various hybrid nano-fluid concentrations (ranging from 0% to 2%) were assessed. The optimal settings were found to raise the average Nusselt number, decrease the temperature, and improve cell efficiency. The efficiency of concentrated solar panels increased from 30.684% at Re = 4000 to 32.438% at Re = 20000 due to improved cooling.
研究了在装有（Al2O3-Cu）/水混合纳米流体的十字形外壳中的湍流强制对流现象。该设计旨在解决半干旱气候条件下由于太阳能电池交叉而导致的聚光太阳能电池板过热问题。 空腔的上部水平壁和左侧垂直壁保持高温，而下部平壁和合适的垂直壁被视为绝热。空腔包含两个入口和一个出口。我们使用有限元方法求解了控制情况的方程，并定义了雷诺值在 4000 到 20000 之间的预期湍流状态。此外，我们还评估了各种混合纳米流体浓度（从 0% 到 2%）的影响。结果发现，最佳设置可提高平均努塞尔特数、降低温度并提高电池效率。由于冷却效果提高，聚光太阳能电池板的效率从 Re = 4000 时的 30.684% 提高到 Re = 20000 时的 32.438%。
{"title":"Computational Study of Crossed-Cavity Hybrid Nanofluid Turbulent Forced Convection for Enhanced Concentrated Solar Panel Cooling","authors":"K. Djermane, S. Kadri","doi":"10.1166/jon.2023.2099","DOIUrl":"https://doi.org/10.1166/jon.2023.2099","url":null,"abstract":"The phenomena of turbulent forced convection were investigated in a cross-shaped enclosure with an (Al2O3-Cu)/water hybrid nano-fluid. This design aims to solve the problem of overheating concentrated solar panels due to crossed solar cells in semiarid climates. The cavity’s upper horizontal and left vertical walls are kept at high temperatures, while the lower flat and suitable vertical walls are considered adiabatic. The cavity contains two inlets and one outlet. Using the finite element method, we solved the equations that controlled our situation and defined the expected turbulent flow regime for Reynolds values between 4000 and 20000. Additionally, the effects of various hybrid nano-fluid concentrations (ranging from 0% to 2%) were assessed. The optimal settings were found to raise the average Nusselt number, decrease the temperature, and improve cell efficiency. The efficiency of concentrated solar panels increased from 30.684% at Re = 4000 to 32.438% at Re = 20000 due to improved cooling.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"6 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139326380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sradharam Swain, G. M. Sarkar, B. Sahoo, A. Rashad
The current investigation aspires to unravel the steady mixed convection flow of Carreau fluid over a permeable vertical stretching/shrinking sheet near a stagnation point. The system of governing equations is reduced into ODEs utilizing appropriate similarity transformations. The similarity transformations are obtained via the Lie scaling group of transformations. Dual similarity solutions are detected depending on the opposing flow parameter for stretching and shrinking cases. The effects of pertinent parameters on the skin friction coefficient, Nusselt number, velocity, and temperature fields are examined in detail. The influence of the suction parameter on the variations of skin friction coefficient for the stretching case shows various behavior than in the shrinking case. However, on the variations of the Nusselt number, a similar trend in both the stretching and shrinking cases is observed. The fluid velocity decreases, and the temperature rises with the increment of non-Newtonian parameter in the upper branch, whereas the lower branch depicts opposite trends. Due to the different characteristics of the lower branch than the upper branch, it is necessary to find a physically reliable solution branch. Thus, a linear temporal stability analysis is conducted based on the sign of the smallest eigenvalue. The smallest eigenvalues are determined numerically using the shooting technique, revealing that the upper branch is the only stable solution branch.
{"title":"Mixed Convection Flow Analysis of Carreau Fluid Over a Vertical Stretching/Shrinking Sheet","authors":"Sradharam Swain, G. M. Sarkar, B. Sahoo, A. Rashad","doi":"10.1166/jon.2023.2085","DOIUrl":"https://doi.org/10.1166/jon.2023.2085","url":null,"abstract":"The current investigation aspires to unravel the steady mixed convection flow of Carreau fluid over a permeable vertical stretching/shrinking sheet near a stagnation point. The system of governing equations is reduced into ODEs utilizing appropriate similarity transformations. The similarity transformations are obtained via the Lie scaling group of transformations. Dual similarity solutions are detected depending on the opposing flow parameter for stretching and shrinking cases. The effects of pertinent parameters on the skin friction coefficient, Nusselt number, velocity, and temperature fields are examined in detail. The influence of the suction parameter on the variations of skin friction coefficient for the stretching case shows various behavior than in the shrinking case. However, on the variations of the Nusselt number, a similar trend in both the stretching and shrinking cases is observed. The fluid velocity decreases, and the temperature rises with the increment of non-Newtonian parameter in the upper branch, whereas the lower branch depicts opposite trends. Due to the different characteristics of the lower branch than the upper branch, it is necessary to find a physically reliable solution branch. Thus, a linear temporal stability analysis is conducted based on the sign of the smallest eigenvalue. The smallest eigenvalues are determined numerically using the shooting technique, revealing that the upper branch is the only stable solution branch.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"9 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139326649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Unprecedented study on Rayleigh-Bénard-Marangoni convection in mono and hybrid nanoliquids in a region confined between two infinite inclined parallel planes. Linear stability analysis is conducted to investigate the stability of longitudinal and transverse rolls. The shooting method is used to obtain the eigenvalues of the boundary value problem with complex coefficients in the case of four different boundary conditions. The inclination angle is chosen in the range [0, 45] and the Rayleigh number is chosen in such a way that the critical Rayleigh number is greater than 0. The thermophysical properties measured at 300 K of twelve nanoliquids and thirty hybrid nanoliquids having a total volume fraction of 0.5% are evaluated using phenomenological laws and mixture theory, and prediction on the onset of convection is made in all cases. C2H6O2-SWCNT (F = 0.972881) advances the onset of convection the most among nanoliquids and C2H6O2-Ag-SWCNT and C2H6O2-Cu-SWCNT (F = 0.972875) among hybrid nanoliquids. Rayleigh-Bénard-Marangoni convective system in an inclined plane is more stable than that in a horizontal plane.
{"title":"Rayleigh-Bénard-Marangoni Convection of Mono and Hybrid Nanoliquids in an Inclined Plane and Solution by Shooting Method","authors":"M. Gayathri, S. Pranesh, P. Siddheshwar","doi":"10.1166/jon.2023.2062","DOIUrl":"https://doi.org/10.1166/jon.2023.2062","url":null,"abstract":"Unprecedented study on Rayleigh-Bénard-Marangoni convection in mono and hybrid nanoliquids in a region confined between two infinite inclined parallel planes. Linear stability analysis is conducted to investigate the stability of longitudinal and transverse rolls. The shooting method is used to obtain the eigenvalues of the boundary value problem with complex coefficients in the case of four different boundary conditions. The inclination angle is chosen in the range [0, 45] and the Rayleigh number is chosen in such a way that the critical Rayleigh number is greater than 0. The thermophysical properties measured at 300 K of twelve nanoliquids and thirty hybrid nanoliquids having a total volume fraction of 0.5% are evaluated using phenomenological laws and mixture theory, and prediction on the onset of convection is made in all cases. C2H6O2-SWCNT (F = 0.972881) advances the onset of convection the most among nanoliquids and C2H6O2-Ag-SWCNT and C2H6O2-Cu-SWCNT (F = 0.972875) among hybrid nanoliquids. Rayleigh-Bénard-Marangoni convective system in an inclined plane is more stable than that in a horizontal plane.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"19 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139329799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An unsteady three-dimensional MHD boundary layer is a fluid flow region near a surface where magnetic fields are present and interact with the fluid flow, causing it to become unsteady. This type of flow is commonly found in various astrophysical and technological applications, such as in plasmas and fusion reactors. The 3D nature of the flow introduces additional complexities to the flow dynamics, making the study and modeling of unsteady MHD boundary layers a challenging and active area of research. The unsteady boundary layer flow of fluid over a moving stagnation surface is theoretically examined in the current work with the impression of a magnetic field. The exact outcomes of the governing equations for the flow domain are obtained by utilizing the shooting phenomena. The specified analytical outcomes are also obtained for some cases. Detailed discussions of the parameters involved are confirmed both physically and graphically. Numerical results for both profiles are presented graphically. The study and modeling of unsteady 3D MHD boundary layers is imperative for a thorough understanding of various physical phenomena, improving the performance of technological systems, and advancing our knowledge of fluid dynamics.
{"title":"Unsteady 3D MHD Boundary Layer Stream for Non-Newtonian Power-Law Fluid Near Stagnation Point of Moving Surfaces","authors":"Mahesha, V. Mohan Babu","doi":"10.1166/jon.2023.2098","DOIUrl":"https://doi.org/10.1166/jon.2023.2098","url":null,"abstract":"An unsteady three-dimensional MHD boundary layer is a fluid flow region near a surface where magnetic fields are present and interact with the fluid flow, causing it to become unsteady. This type of flow is commonly found in various astrophysical and technological applications, such as in plasmas and fusion reactors. The 3D nature of the flow introduces additional complexities to the flow dynamics, making the study and modeling of unsteady MHD boundary layers a challenging and active area of research. The unsteady boundary layer flow of fluid over a moving stagnation surface is theoretically examined in the current work with the impression of a magnetic field. The exact outcomes of the governing equations for the flow domain are obtained by utilizing the shooting phenomena. The specified analytical outcomes are also obtained for some cases. Detailed discussions of the parameters involved are confirmed both physically and graphically. Numerical results for both profiles are presented graphically. The study and modeling of unsteady 3D MHD boundary layers is imperative for a thorough understanding of various physical phenomena, improving the performance of technological systems, and advancing our knowledge of fluid dynamics.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"27 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139329807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Swapan K. Pandit, A. Chattopadhyay, Rupchand Malo, Krishno D. Goswami
This study explores the significant impacts of thin baffles and magnetic field dependent viscosity on magnetohydrodynamic (MHD) thermogravitational convection of Cu-Al2O3 (50%–50%) water hybrid nanoliquid in a cavity. Considering different arrangements of baffle sticks on both the vertical walls, four geometrical configurations (Case-I, Case-II, Case-III and Case-IV) have been analyzed. Numerical simulation has been performed for the governing Navier-Stokes (N-S) equations in streamfunction - vorticity form having energy equation. These coupled equations are solved by proposing a higher-order compact finite difference method. The combination of five important aspects (hybrid nanofluid, multiple baffles, magnetic field dependent viscosity (MFDV), magnetic field and compact computation) signifies the novelty of this work. Fluid flow and transportation of thermal energy within the stipulated domain are presented for various flow pertinent parameters. The outcomes show that the increase in number of baffles diminishes the average Nusselt number values. It is concluded here that an increase in Hartmann number from 0 to 90 leads to a decrease in average Nusselt number up to 23.7% for Case-I, 23.8% for Case-II, 21.2% for Case-III and 28% for Case-IV in presence of MFDV effects.
{"title":"Thermogravitational Convection in a Multiple Baffled Enclosure Filled with Magneto-Hybrid Nanofluid Subjected to Magnetic Field Dependent Viscosity","authors":"Swapan K. Pandit, A. Chattopadhyay, Rupchand Malo, Krishno D. Goswami","doi":"10.1166/jon.2023.2051","DOIUrl":"https://doi.org/10.1166/jon.2023.2051","url":null,"abstract":"This study explores the significant impacts of thin baffles and magnetic field dependent viscosity on magnetohydrodynamic (MHD) thermogravitational convection of Cu-Al2O3 (50%–50%) water hybrid nanoliquid in a cavity. Considering different arrangements of baffle sticks on both the vertical walls, four geometrical configurations (Case-I, Case-II, Case-III and Case-IV) have been analyzed. Numerical simulation has been performed for the governing Navier-Stokes (N-S) equations in streamfunction - vorticity form having energy equation. These coupled equations are solved by proposing a higher-order compact finite difference method. The combination of five important aspects (hybrid nanofluid, multiple baffles, magnetic field dependent viscosity (MFDV), magnetic field and compact computation) signifies the novelty of this work. Fluid flow and transportation of thermal energy within the stipulated domain are presented for various flow pertinent parameters. The outcomes show that the increase in number of baffles diminishes the average Nusselt number values. It is concluded here that an increase in Hartmann number from 0 to 90 leads to a decrease in average Nusselt number up to 23.7% for Case-I, 23.8% for Case-II, 21.2% for Case-III and 28% for Case-IV in presence of MFDV effects.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"54 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139330449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The fluid flow in a non-parallel configuration exists in the electronic heat removal devices, microchannel heat sinks, and angled confusers/diffusers. The fluids in these applications are prone to flow separation and bifurcations. To deal with such type of problems, a novel idea of a converging or diverging type Riga plate channel is introduced in this study. The Riga plates are utilised to produce the cross-flow magnetic and electric fields which give rise to an exponentially decaying Lorentz force. Also, a porous matrix with variable permeability is considered to fill the Riga plate channel. The thermal equilibrium state between the hybrid nanofluid and porous media is ignored i.e., a local thermal non-equilibrium (LTNE) approach is adopted to model the energy balance equations. The dimension-free form of the guiding equations is tackled by using the Chebyshev pseudospectral quasi-linearization method. The heat transfer rate is respectively incremented by 21.42% and 63.12% in the converging and diverging flow regimes, with the inclusion of a Riga Sheet. The skin friction coefficient is depressed with modified Hartmann number (Ha*) and porosity (ε) for the converging/diverging flow regime. The LTNE state alters to the LTE with Nield number (Ni), thermal conductivity ratio (γ) and ε.
{"title":"A Local Thermal Non-Equilibrium Approach to an Electromagnetic Hybrid Nanofluid Flow in a Non-Parallel Riga Plate Channel","authors":"T. Sharma, Rakesh Kumar, Ali J. Chamkha","doi":"10.1166/jon.2023.2104","DOIUrl":"https://doi.org/10.1166/jon.2023.2104","url":null,"abstract":"The fluid flow in a non-parallel configuration exists in the electronic heat removal devices, microchannel heat sinks, and angled confusers/diffusers. The fluids in these applications are prone to flow separation and bifurcations. To deal with such type of problems, a novel idea of a converging or diverging type Riga plate channel is introduced in this study. The Riga plates are utilised to produce the cross-flow magnetic and electric fields which give rise to an exponentially decaying Lorentz force. Also, a porous matrix with variable permeability is considered to fill the Riga plate channel. The thermal equilibrium state between the hybrid nanofluid and porous media is ignored i.e., a local thermal non-equilibrium (LTNE) approach is adopted to model the energy balance equations. The dimension-free form of the guiding equations is tackled by using the Chebyshev pseudospectral quasi-linearization method. The heat transfer rate is respectively incremented by 21.42% and 63.12% in the converging and diverging flow regimes, with the inclusion of a Riga Sheet. The skin friction coefficient is depressed with modified Hartmann number (Ha*) and porosity (ε) for the converging/diverging flow regime. The LTNE state alters to the LTE with Nield number (Ni), thermal conductivity ratio (γ) and ε.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"68 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139326422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main objective of the paper is to explore the effects of Soret and Dufour on MHD mixed bioconvection of nanofluid in a flat channel with chemical reaction, radiation, Joule heating and partial (velocity) slip. The related ordinary differential equations are comprised of velocity, energy, nanoparticle concentration, solutal concentration and microorganisms density are solved analytically subject to physically appropriate boundary conditions using homotopy analysis method (HAM). The dimensionless skin friction, heat and mass transport are discussed through plots by varying different physical parameters. The transport of heat enhances with Brinkman number but it increases gradually with thermal radiation. The fluid velocity reduces by the velocity slip, while it increases by raising the Hartmann number. The temperature of the fluid lowered due to the surplus thermal radiation. The dufour number and velocity slip create opposite effect in solutal concentration.
{"title":"Partial Slip and Cross-Diffusion Effects on Magnetohydrodynamic Mixed Bioconvection Flow in a Channel with Chemical Reaction","authors":"S. P. Geetha, S. Sivasankaran, M. Bhuvaneswari","doi":"10.1166/jon.2023.2063","DOIUrl":"https://doi.org/10.1166/jon.2023.2063","url":null,"abstract":"The main objective of the paper is to explore the effects of Soret and Dufour on MHD mixed bioconvection of nanofluid in a flat channel with chemical reaction, radiation, Joule heating and partial (velocity) slip. The related ordinary differential equations are comprised of velocity, energy, nanoparticle concentration, solutal concentration and microorganisms density are solved analytically subject to physically appropriate boundary conditions using homotopy analysis method (HAM). The dimensionless skin friction, heat and mass transport are discussed through plots by varying different physical parameters. The transport of heat enhances with Brinkman number but it increases gradually with thermal radiation. The fluid velocity reduces by the velocity slip, while it increases by raising the Hartmann number. The temperature of the fluid lowered due to the surplus thermal radiation. The dufour number and velocity slip create opposite effect in solutal concentration.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"23 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139327507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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