The present study has been investigated to the consequence of the magnetic parameter, Grashof number, modified Grashof number, Prandtl number, thermal radiation parameter, Brownian motion parameter, thermophoresis parameter, heat generation parameter, Schmidt number, Biot number, stretching parameter, Lewis number, and chemical reaction parameter, respectively, over a stretching wedge of the magnetohydrodynamic (MHD) BL nanofluid flow. The main goal of this paper is to numerically investigate the nature of the MHD BL nanofluid flow along a stretching wedge-shaped surface with radiation, heat source, and chemical reaction parameters. The fundamental equations has been transformed into ordinary differential equations (ODEs) by the usual transformation. The numerical solutions are found by employing Runge-Kutta fourth-order method by exploiting symbolic software MATLAB via the shooting method. The novelty of the current study is implicated in the area of fluid dynamics to solve nonlinear differential equations numerically and is an important contribution to the field of nanofluids flow. Numerical solutions reveal that the concerned physical parameters lead to progress in the skin friction factor, rate of change of heat transfer as well as the rate of change of concentration. Brownian motion and thermophoresis parameters play a crucial role in the variation of temperature and concentration profiles and also in the development of thermal and concentration boundary layers.
{"title":"Magnetohydrodynamic Mixed Convection Heat and Mass Transfer of Nanofluid Flow Over a Stretching Wedge-Shaped Surface with the Effect of Thermophoresis and Brownian Motion","authors":"Umme Hani, M. Ali, M. S. Alam","doi":"10.1166/jon.2023.2042","DOIUrl":"https://doi.org/10.1166/jon.2023.2042","url":null,"abstract":"The present study has been investigated to the consequence of the magnetic parameter, Grashof number, modified Grashof number, Prandtl number, thermal radiation parameter, Brownian motion parameter, thermophoresis parameter, heat generation parameter, Schmidt number, Biot number, stretching\u0000 parameter, Lewis number, and chemical reaction parameter, respectively, over a stretching wedge of the magnetohydrodynamic (MHD) BL nanofluid flow. The main goal of this paper is to numerically investigate the nature of the MHD BL nanofluid flow along a stretching wedge-shaped surface with\u0000 radiation, heat source, and chemical reaction parameters. The fundamental equations has been transformed into ordinary differential equations (ODEs) by the usual transformation. The numerical solutions are found by employing Runge-Kutta fourth-order method by exploiting symbolic software MATLAB\u0000 via the shooting method. The novelty of the current study is implicated in the area of fluid dynamics to solve nonlinear differential equations numerically and is an important contribution to the field of nanofluids flow. Numerical solutions reveal that the concerned physical parameters lead\u0000 to progress in the skin friction factor, rate of change of heat transfer as well as the rate of change of concentration. Brownian motion and thermophoresis parameters play a crucial role in the variation of temperature and concentration profiles and also in the development of thermal and concentration\u0000 boundary layers.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"116 S148","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41266506","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 stability analysis of tri-hybrid nanofluid is examined theoretically in the presence of three types of gravity modulation. Normal mode techniques have been carried out for linear stability analysis, and the truncated Fourier series method is used for non-linear analysis. We observe both stationary and oscillatory convection is possible in the bottom-heavy case, and the onset of convection gets delayed in stationary in comparison to oscillatory. We also observe the onset of convection is earlier in the case of top-heavy with respect to bottom-heavy. Heat and mass transport start earlier in the day–night profile in comparison to other profiles of gravity modulation. In the graph of nusselt number, mass transfer of the first particle increases with an increase in Rn1 value while other two concentration Rayleigh numbers (Rn2, Rn3) does not have any effect on first concentration nusselt number. If we generalize the problem for n-different types of nanoparticles, then two cases may be possible (1) Top-heavy-ordinary nanofluids will be the most stabilizing case. (2) Bottom-heavy-nanofluids with n-type particles will be the most stabilizing case. The most stabilizing case is possible with the same ratio of Rn in the top-heavy, whereas the opposite result is found in the bottom-heavy.
{"title":"Instability Analysis of Tri-Hybrid Nanofluid Under the Influence of Three Types of Gravity Modulation","authors":"Awanish Kumar, B. Bhadauria, Shilpee","doi":"10.1166/jon.2023.2028","DOIUrl":"https://doi.org/10.1166/jon.2023.2028","url":null,"abstract":"The stability analysis of tri-hybrid nanofluid is examined theoretically in the presence of three types of gravity modulation. Normal mode techniques have been carried out for linear stability analysis, and the truncated Fourier series method is used for non-linear analysis. We observe\u0000 both stationary and oscillatory convection is possible in the bottom-heavy case, and the onset of convection gets delayed in stationary in comparison to oscillatory. We also observe the onset of convection is earlier in the case of top-heavy with respect to bottom-heavy. Heat and mass transport\u0000 start earlier in the day–night profile in comparison to other profiles of gravity modulation. In the graph of nusselt number, mass transfer of the first particle increases with an increase in Rn1 value while other two concentration Rayleigh numbers (Rn2,\u0000 Rn3) does not have any effect on first concentration nusselt number. If we generalize the problem for n-different types of nanoparticles, then two cases may be possible (1) Top-heavy-ordinary nanofluids will be the most stabilizing case. (2) Bottom-heavy-nanofluids with n-type\u0000 particles will be the most stabilizing case. The most stabilizing case is possible with the same ratio of Rn in the top-heavy, whereas the opposite result is found in the bottom-heavy.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48593620","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}
This work deals with an analytical study on the initiation of oscillatory convection in a rheological nanofluid saturating anisotropic porous layer with inclusion of vertical AC electric field using modified boundary conditions with negligible flux of volume fraction of nanoparticles. The rheological properties of the nanofluid are described using Oldroyd model. The Darcy model extended by Brinkman model is deployed to characterize the solid matrix behavior. The used model for nanofluid with inclusion of electric field integrates the additional effect of electrophoresis with that of thermophoresis and Brownian motion in the conservation equations of motion. The partial differential equations are simplified to non-dimensional linear equations using infinitesimal perturbations, Boussinesq approximation, normal mode technique and linearized stability theory. The characteristic equation is solved analytically for stress-free boundary conditions and the expressions for Rayleigh number of non-oscillatory and oscillatory modes initiation are determined. The oscillatory modes are found to occur for both the cases of top-/bottom-heavy nanoparticles distributions. The electric Rayleigh number, thermal Prandtl number and stress relaxation parameter advances whereas the Brinkman-Darcy number are found to delay initiation of both stationary and oscillatory convection.
{"title":"Oscillatory Modes on the Onset of Electrohydrodynamic Instability in Oldroydian Nanofluid Saturated Anisotropic Porous Layer","authors":"Veena Sharma, None Kavita, Anuradha Chowdhary","doi":"10.1166/jon.2023.2037","DOIUrl":"https://doi.org/10.1166/jon.2023.2037","url":null,"abstract":"This work deals with an analytical study on the initiation of oscillatory convection in a rheological nanofluid saturating anisotropic porous layer with inclusion of vertical AC electric field using modified boundary conditions with negligible flux of volume fraction of nanoparticles. The rheological properties of the nanofluid are described using Oldroyd model. The Darcy model extended by Brinkman model is deployed to characterize the solid matrix behavior. The used model for nanofluid with inclusion of electric field integrates the additional effect of electrophoresis with that of thermophoresis and Brownian motion in the conservation equations of motion. The partial differential equations are simplified to non-dimensional linear equations using infinitesimal perturbations, Boussinesq approximation, normal mode technique and linearized stability theory. The characteristic equation is solved analytically for stress-free boundary conditions and the expressions for Rayleigh number of non-oscillatory and oscillatory modes initiation are determined. The oscillatory modes are found to occur for both the cases of top-/bottom-heavy nanoparticles distributions. The electric Rayleigh number, thermal Prandtl number and stress relaxation parameter advances whereas the Brinkman-Darcy number are found to delay initiation of both stationary and oscillatory convection.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136350622","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 effects of melting heat transfer, thermal radiation, and porous medium on steady, 2-D, viscous, incompressible, magneto hydrodynamic nano-fluid flow concluded a linearly extending sheet in the occurrence of viscous dissipation, as well as first and subsequent order slip effects, were always considered in this numerical research. In this research, appropriate similarity variables were employed to turn the controlling nonlinear partial differentiated equations hooked on a system of linked nonlinear ordinary differential comparisons that are mathematically explained using the Runge-Kutta approach with a firing scheme. The consequence of several pertinent limitations on rapidity profiles, temperature profiles, and attentiveness profiles is graphically explored also thoroughly interpreted. In this work, images and tables were utilized to represent various progressive values of non-dimensionalized parameters, while numerical data was employed to examine variations in skin-friction, heat, and mass transmission charges. The present study of my observation compared with previous studies in a limiting case. A reliable agreement between the numeric values is achieved here. The velocity profiles in this issue decrease as the values of the Suction/Injection fluid parameter as well as the Magnetic field limitation growth. Temperature profiles rise as the impacts of thermophoresis and Brownian motion become stronger. When the value of the Dufour number rises, so do the temperature profiles. Thermophoresis parameter expansions results in enhanced nanoparticle volume concentration distributions, whereas Brownian motion effects produces the opposite effects. As the Soret number parameter increases, so do the concentration profiles. This melting heat transfer study work includes numerous industrial applications, including casting, welding, and magma solidification, permafrost melting and ground thawing, and so on.
{"title":"Melting Heat Transfer on Magnetohydrodynamics-Nanofluid Boundary Layer Flow Past a Stretching Sheet: Thermal Radiation and Viscous Dissipation Effects","authors":"P. Narender, T. R. Goud","doi":"10.1166/jon.2023.2040","DOIUrl":"https://doi.org/10.1166/jon.2023.2040","url":null,"abstract":"The effects of melting heat transfer, thermal radiation, and porous medium on steady, 2-D, viscous, incompressible, magneto hydrodynamic nano-fluid flow concluded a linearly extending sheet in the occurrence of viscous dissipation, as well as first and subsequent order slip effects,\u0000 were always considered in this numerical research. In this research, appropriate similarity variables were employed to turn the controlling nonlinear partial differentiated equations hooked on a system of linked nonlinear ordinary differential comparisons that are mathematically explained\u0000 using the Runge-Kutta approach with a firing scheme. The consequence of several pertinent limitations on rapidity profiles, temperature profiles, and attentiveness profiles is graphically explored also thoroughly interpreted. In this work, images and tables were utilized to represent various\u0000 progressive values of non-dimensionalized parameters, while numerical data was employed to examine variations in skin-friction, heat, and mass transmission charges. The present study of my observation compared with previous studies in a limiting case. A reliable agreement between the numeric\u0000 values is achieved here. The velocity profiles in this issue decrease as the values of the Suction/Injection fluid parameter as well as the Magnetic field limitation growth. Temperature profiles rise as the impacts of thermophoresis and Brownian motion become stronger. When the value of the\u0000 Dufour number rises, so do the temperature profiles. Thermophoresis parameter expansions results in enhanced nanoparticle volume concentration distributions, whereas Brownian motion effects produces the opposite effects. As the Soret number parameter increases, so do the concentration profiles.\u0000 This melting heat transfer study work includes numerous industrial applications, including casting, welding, and magma solidification, permafrost melting and ground thawing, and so on.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47240884","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}
A steady two-dimensional axisymmetric incompressible flow over an exponentially stretching bullet-shaped surface has been considered. The present work is mainly focused on fluid flow by the effect of multiple slips. The governing partial differential equations and auxiliary boundary conditions have been converted into higher-order equations by using assisting similarity transformations. These higher-order ODEs are then transformed into a 1st-order system of LDEs by the method of spectral quasi-linearization (SQLM). The validity, accuracy, and convergence of the solution have been performed by using SQLM. The fluid velocity, temperature, skin friction coefficient, and Nusselt number have been depicted graphically for the mentioned parameters as also the numerical values of velocity gradient, and Nusselt number in a table. The numerical investigation shows that the velocity gradient enhances due to the parameter of magnetic, thermal slip, and Prandtl number whereas the remaining parameters have a reverse effect on it. The heat transfer rate reduces for the parameters of magnetic, multiple slip, injection, and viscous dissipation but suction and heat generation have a reverse effect on it. The results of in this work have been justified due to the validity and accuracy of the present problem. Due to the endless application of Newtonian fluids in engineering and industry, no attempt has been taken to inspect the MHD flow with a dual slip effect along with exponential stretching bullet-shaped surface. Also, the current work is of immediate interest to those systems that are highly influenced by the heat transfer process and desired product quality.
{"title":"Numerical Analysis of Velocity and Thermal Wall Slip Effects on the Boundary Layer Flow Over an Exponentially Stretching Bullet-Shaped Object in Presence of Suction and Injection","authors":"M. Ali, M. A. Alim","doi":"10.1166/jon.2023.2041","DOIUrl":"https://doi.org/10.1166/jon.2023.2041","url":null,"abstract":"A steady two-dimensional axisymmetric incompressible flow over an exponentially stretching bullet-shaped surface has been considered. The present work is mainly focused on fluid flow by the effect of multiple slips. The governing partial differential equations and auxiliary boundary\u0000 conditions have been converted into higher-order equations by using assisting similarity transformations. These higher-order ODEs are then transformed into a 1st-order system of LDEs by the method of spectral quasi-linearization (SQLM). The validity, accuracy, and convergence of the solution\u0000 have been performed by using SQLM. The fluid velocity, temperature, skin friction coefficient, and Nusselt number have been depicted graphically for the mentioned parameters as also the numerical values of velocity gradient, and Nusselt number in a table. The numerical investigation shows\u0000 that the velocity gradient enhances due to the parameter of magnetic, thermal slip, and Prandtl number whereas the remaining parameters have a reverse effect on it. The heat transfer rate reduces for the parameters of magnetic, multiple slip, injection, and viscous dissipation but suction\u0000 and heat generation have a reverse effect on it. The results of in this work have been justified due to the validity and accuracy of the present problem. Due to the endless application of Newtonian fluids in engineering and industry, no attempt has been taken to inspect the MHD flow with a\u0000 dual slip effect along with exponential stretching bullet-shaped surface. Also, the current work is of immediate interest to those systems that are highly influenced by the heat transfer process and desired product quality.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46051777","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}
P. Umadevi, A. Begum, Ali J. Chamkha, G. Maheshwari
In presents of a magnetic field, an enclosure filled with ferro-particle suspended nanofluid is subjected to a numerical analysis to investigate natural convective heat transfer. At the center of the enclosure is a heat conducting and generating solid body, and the enclosure is influenced by four different thermal boundary conditions. To solve the governing equation, a Fortran algorithm based on the finite volume approach was created. The numerical approach used in this study produces consistent results for a variety of non-dimensional parameters like Rayleigh number (104 ≤ Ra ≤ 106), Hartmann number (0 ≤ Ha ≤ 100), solid volume fraction (0 ≤ φ ≤ 0.2) and distributed wall temperature. Streamlines, isotherms, and the Nusselt number graph are used to describe the flow and heat transfer properties. Based on this study, It has been noted that improved heat transfer for lower Hartmann number with higher Rayleigh number particularly along sinusoidal wall. For the low Hartmann number, the fluid flow enhances for higher Rayleigh number. In particular, the presence of ferro-particle suspended nanofluid enhances the heat transfer rate. Moreover, this study has found that the inclusion of magnetic fields and nanoparticles can increase heat transfer by up to 60%. The suggested methods in this research can assist manufacturers improve efficiency without increasing heat generator space in industrial applications for cooling or heating.
{"title":"Numerical Analysis of Magnetic Field Effect on Ferro Particle Suspended Nanofluid Filled Square Enclosure Consist of Heat Generating Body","authors":"P. Umadevi, A. Begum, Ali J. Chamkha, G. Maheshwari","doi":"10.1166/jon.2023.2043","DOIUrl":"https://doi.org/10.1166/jon.2023.2043","url":null,"abstract":"In presents of a magnetic field, an enclosure filled with ferro-particle suspended nanofluid is subjected to a numerical analysis to investigate natural convective heat transfer. At the center of the enclosure is a heat conducting and generating solid body, and the enclosure is influenced\u0000 by four different thermal boundary conditions. To solve the governing equation, a Fortran algorithm based on the finite volume approach was created. The numerical approach used in this study produces consistent results for a variety of non-dimensional parameters like Rayleigh number (104\u0000 ≤ Ra ≤ 106), Hartmann number (0 ≤ Ha ≤ 100), solid volume fraction (0 ≤ φ ≤ 0.2) and distributed wall temperature. Streamlines, isotherms, and the Nusselt number graph are used to describe the flow and heat transfer properties. Based on this study,\u0000 It has been noted that improved heat transfer for lower Hartmann number with higher Rayleigh number particularly along sinusoidal wall. For the low Hartmann number, the fluid flow enhances for higher Rayleigh number. In particular, the presence of ferro-particle suspended nanofluid enhances\u0000 the heat transfer rate. Moreover, this study has found that the inclusion of magnetic fields and nanoparticles can increase heat transfer by up to 60%. The suggested methods in this research can assist manufacturers improve efficiency without increasing heat generator space in industrial applications\u0000 for cooling or heating.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43903402","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}
Hozaifa A. Mohamed, Majed M. Alhazmy, F. Mansour, E. Negeed
The present research aims to enhance the convective heat transfer coefficient inside the tube of the double pipe heat exchangers, this is carried out by mixing the water with copper oxide (CuO) nanoparticles. In this study, the effects of nanofluid with different volume concentrations from 0 to 0.4%, flowrates of nanofluid inside the tube, and water flow through the annulus, and inlet temperature inside the tube were examined on the Nusselt number. From the analysis, experiential data found nanoparticles have a significant enhancement of the convective heat transfer coefficient inside the tube of the double pipe. The heat transfer coefficient inside the tube increases as the Reynolds numbers of the flow inside the tube, and water flow through the annulus increase. The convective heat transfer coefficients reached maximum values at 0.35% of the volume concentrations of CuO nanoparticles and then decreased as the increase of the volume concentrations increases. The fiction factor increases as the volume concentrations of nanoparticles increases. Empirical correlations are presented describing the Nusselt number and the friction factor of the nanofluid flow inside the tube of the double pipe and concealing the affecting parameters in such process.
{"title":"Heat Transfer Enhancement Using CuO Nanofluid in a Double Pipe U-Bend Heat Exchanger","authors":"Hozaifa A. Mohamed, Majed M. Alhazmy, F. Mansour, E. Negeed","doi":"10.1166/jon.2023.2014","DOIUrl":"https://doi.org/10.1166/jon.2023.2014","url":null,"abstract":"The present research aims to enhance the convective heat transfer coefficient inside the tube of the double pipe heat exchangers, this is carried out by mixing the water with copper oxide (CuO) nanoparticles. In this study, the effects of nanofluid with different volume concentrations\u0000 from 0 to 0.4%, flowrates of nanofluid inside the tube, and water flow through the annulus, and inlet temperature inside the tube were examined on the Nusselt number. From the analysis, experiential data found nanoparticles have a significant enhancement of the convective heat transfer coefficient\u0000 inside the tube of the double pipe. The heat transfer coefficient inside the tube increases as the Reynolds numbers of the flow inside the tube, and water flow through the annulus increase. The convective heat transfer coefficients reached maximum values at 0.35% of the volume concentrations\u0000 of CuO nanoparticles and then decreased as the increase of the volume concentrations increases. The fiction factor increases as the volume concentrations of nanoparticles increases. Empirical correlations are presented describing the Nusselt number and the friction factor of the nanofluid\u0000 flow inside the tube of the double pipe and concealing the affecting parameters in such process.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48849962","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}
Buoyancy-driven convective flow and heat transfer characteristics in a Newtonian nanoliquid-saturated porous square enclosure are analyzed numerically using a local thermal non-equilibrium model. An enclosure’s horizontal walls are considered free–free and adiabatic, and the vertical walls are free–free isothermal boundaries. The dimensionless governing equations are solved using a central finite difference scheme with second-degree accuracy, and the results are in satisfactory agreement with the earlier works. The impact of various parameters on streamlines and isotherms is analyzed and depicted graphically. The effect of Darcy number, thermal Rayleigh number, and the ratio of thermal conductivities slow down the liquid flow. The temperature distribution is maximum at sidewalls and diminishes the amount of heat transport. The opposite phenomenon is observed for the solute Rayleigh number and interphase transfer coefficient of liquid-particle phases. For large values of interphase heat transfer coefficients, liquid-solid and liquid-particle are said to be in the local thermal equilibrium phase. The amount of heat transfer increases with an increasing interphase heat transfer coefficient and the ratio of the phases’ thermal conductivities. Results of local thermal equilibrium situation can be obtained as the particular case of the study. The amount of heat transfer is maximum in the local thermal non-equilibrium situation, and enhanced by 0.09% compared with the local thermal equilibrium situation. Heat transport is 0.74% less in the sparsely packed porous medium compared with the low-porosity medium.
{"title":"Natural Convection in a Newtonian Nanoliquid-Saturated Porous Enclosure with Local Thermal Non-Equilibrium Effect","authors":"C. Siddabasappa, K. Aishwarya, Babitha","doi":"10.1166/jon.2023.2048","DOIUrl":"https://doi.org/10.1166/jon.2023.2048","url":null,"abstract":"Buoyancy-driven convective flow and heat transfer characteristics in a Newtonian nanoliquid-saturated porous square enclosure are analyzed numerically using a local thermal non-equilibrium model. An enclosure’s horizontal walls are considered free–free and adiabatic, and\u0000 the vertical walls are free–free isothermal boundaries. The dimensionless governing equations are solved using a central finite difference scheme with second-degree accuracy, and the results are in satisfactory agreement with the earlier works. The impact of various parameters on streamlines\u0000 and isotherms is analyzed and depicted graphically. The effect of Darcy number, thermal Rayleigh number, and the ratio of thermal conductivities slow down the liquid flow. The temperature distribution is maximum at sidewalls and diminishes the amount of heat transport. The opposite phenomenon\u0000 is observed for the solute Rayleigh number and interphase transfer coefficient of liquid-particle phases. For large values of interphase heat transfer coefficients, liquid-solid and liquid-particle are said to be in the local thermal equilibrium phase. The amount of heat transfer increases\u0000 with an increasing interphase heat transfer coefficient and the ratio of the phases’ thermal conductivities. Results of local thermal equilibrium situation can be obtained as the particular case of the study. The amount of heat transfer is maximum in the local thermal non-equilibrium\u0000 situation, and enhanced by 0.09% compared with the local thermal equilibrium situation. Heat transport is 0.74% less in the sparsely packed porous medium compared with the low-porosity medium.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45721938","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}
This paper presents a numerical analysis study of the dynamic and thermal performance of a convective flow of water-copper nanofluids in a double-pass flat solar collector. The flow inside the confined space between the glazing and the insulation is governed by the continuity, momentum, and energy equations. The problem addressed is solved via a CFD ANSYS code using the finite volume method to discretize the equations of the mathematical model. The dynamic and thermal fields are obtained for different values of the volume fraction (φ = 0%, φ = 3%, and φ = 8%). These results are compared with other results mentioned in the literature. The results obtained allowed us to define the influence of these different parameters on the convective nanofluid flow in the solar collector. The increase in the volume fraction further promotes heat transfer. The presence of nanoparticles expects a critical part of the convective heat exchange.
{"title":"Numerical Analysis Study of a Convective Flow of Nanofluids in a Double-Pass Solar Collector","authors":"K. Rakrak, A. Benahmed, S. Belabbes, T. Tayebi","doi":"10.1166/jon.2023.2008","DOIUrl":"https://doi.org/10.1166/jon.2023.2008","url":null,"abstract":"This paper presents a numerical analysis study of the dynamic and thermal performance of a convective flow of water-copper nanofluids in a double-pass flat solar collector. The flow inside the confined space between the glazing and the insulation is governed by the continuity, momentum,\u0000 and energy equations. The problem addressed is solved via a CFD ANSYS code using the finite volume method to discretize the equations of the mathematical model. The dynamic and thermal fields are obtained for different values of the volume fraction (φ = 0%, φ = 3%,\u0000 and φ = 8%). These results are compared with other results mentioned in the literature. The results obtained allowed us to define the influence of these different parameters on the convective nanofluid flow in the solar collector. The increase in the volume fraction further promotes\u0000 heat transfer. The presence of nanoparticles expects a critical part of the convective heat exchange.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44020532","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}
N. Ghoudi, F. Mebarek‐Oudina, M. Bouabid, R. Choudhari, M. Magherbi
The problem of non-Newtonian fluid flow has taken considerable interest and has been the subject of several work in latest years due to its various requests in different fields of engineering, in particular the interest in the problems of heat transfer in non-Newtonian liquids, such as lubrication, hot rolling, cooling problem and drag reduction. Here, mixed convection heat transport and its related entropy production in a porous channel with circular obstacle saturated via non-Newtonian power law liquid has been scrutinized. The influences on entropy production of the power law index, the Reynolds number, the Rayleigh number and the Darcy number are investigated. Being a novelty of this work, an optimization study of the thermodynamic irreversibility as a function of the channel inclination angle and the power law index is undertaken. The governing equations of the problem are solved employing the COMSOL software. Outcomes illustrate that the governing parameters strongly affect the entropy production. The thermal entropy generation is maximal at low value of power law index and high value of Reynolds number. The effect of Reynolds number become insignificant at relatively high power law index. At fixed Reynolds number value, a rise in the power index (n) leads to a reduce in the thermal entropy. This decrease is tiny, at low value of Reynolds number (Re) and turn into increasingly considerable as Re rises. The streamlines show the existence of two recirculation zones just after the circular obstacle, whose existence depends on both Re and power law index. Results show that the greatest variation relating to the inclination angle is for power law index equal to 0.4. Results indicate also that, at low Darcy number and relatively high power law index, the intrinsic effect of the modified Darcy number on Darcy viscous irreversibility become pronounced giving a sharp increase in the total entropy production.
{"title":"Second Law Investigation in a Non-Newtonian Liquid Flow in a Porous Channel with Circular Obstacle","authors":"N. Ghoudi, F. Mebarek‐Oudina, M. Bouabid, R. Choudhari, M. Magherbi","doi":"10.1166/jon.2023.2045","DOIUrl":"https://doi.org/10.1166/jon.2023.2045","url":null,"abstract":"The problem of non-Newtonian fluid flow has taken considerable interest and has been the subject of several work in latest years due to its various requests in different fields of engineering, in particular the interest in the problems of heat transfer in non-Newtonian liquids, such\u0000 as lubrication, hot rolling, cooling problem and drag reduction. Here, mixed convection heat transport and its related entropy production in a porous channel with circular obstacle saturated via non-Newtonian power law liquid has been scrutinized. The influences on entropy production of the\u0000 power law index, the Reynolds number, the Rayleigh number and the Darcy number are investigated. Being a novelty of this work, an optimization study of the thermodynamic irreversibility as a function of the channel inclination angle and the power law index is undertaken. The governing equations\u0000 of the problem are solved employing the COMSOL software. Outcomes illustrate that the governing parameters strongly affect the entropy production. The thermal entropy generation is maximal at low value of power law index and high value of Reynolds number. The effect of Reynolds number become\u0000 insignificant at relatively high power law index. At fixed Reynolds number value, a rise in the power index (n) leads to a reduce in the thermal entropy. This decrease is tiny, at low value of Reynolds number (Re) and turn into increasingly considerable as Re rises. The\u0000 streamlines show the existence of two recirculation zones just after the circular obstacle, whose existence depends on both Re and power law index. Results show that the greatest variation relating to the inclination angle is for power law index equal to 0.4. Results indicate also that,\u0000 at low Darcy number and relatively high power law index, the intrinsic effect of the modified Darcy number on Darcy viscous irreversibility become pronounced giving a sharp increase in the total entropy production.","PeriodicalId":47161,"journal":{"name":"Journal of Nanofluids","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41392804","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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