Combined effects of Soret(thermal-diffusion) and Dufour(diffusion-thermo) in MHD stagnation point flow by a permeable stretching cylinder were studied. Analysis was examined in the presence of heat generation/absorpti...Combined effects of Soret(thermal-diffusion) and Dufour(diffusion-thermo) in MHD stagnation point flow by a permeable stretching cylinder were studied. Analysis was examined in the presence of heat generation/absorption and chemical reaction. The laws of conservation of mass, momentum, energy and concentration are found to lead to the mathematical development of the problem. Suitable transformations were used to convert the nonlinear partial differential equations into the ordinary differential equations. The series solutions of boundary layer equations through momentum, energy and concentration equations were obtained.Convergence of the developed series solutions was discussed via plots and numerical values. The behaviors of different physical parameters on the velocity components, temperature and concentration were obtained. Numerical values of Nusselt number, skin friction and Sherwood number with different parameters were computed and analyzed. It is found that Dufour and Soret numbers result in the enhancement of temperature and concentration distributions, respectively.展开更多
This research explored the effects of an angled magnetic field, Brownian motion, and thermophoresis on the flow of an electrically conducting and chemically reacting Casson nanofluid under the influence of the Soret-D...This research explored the effects of an angled magnetic field, Brownian motion, and thermophoresis on the flow of an electrically conducting and chemically reacting Casson nanofluid under the influence of the Soret-Dufour mechanism. A set of partial differential equations is generated by the flow mode. The governing partial differential equations are solved numerically using the spectral collocation method after being transformed to self-similar forms. The effect of various fluid parameters on the velocity profile, temperature profile, and nanoparticle concentration is addressed. A quantitative agreement is observed when previous findings are compared to the current results. The skin friction, local Nusselt number, and local Sherwood number are also examined, and the results are presented in the table. This study discovered that the inclined magnetic field has a significant impact on the flow of the electrically conducting fluid by delaying its mobility within the boundary layer. The plastic dynamic viscosity, which acts as a barrier to fluid flow, is shown to degenerate the fluid velocity when the Casson parameter is increased. As a consequence, the findings may be used to improve thermal science instruments and increase industrial output.展开更多
In this work, the Micropolar fluid flow and heat and mass transfer past a horizontal nonlinear stretching sheet through porous medium is studied including the Soret-Dufour effect in the presence of suction. A uniform ...In this work, the Micropolar fluid flow and heat and mass transfer past a horizontal nonlinear stretching sheet through porous medium is studied including the Soret-Dufour effect in the presence of suction. A uniform magnetic field is applied transversely to the direction of the flow. The governing differential equations of the problem have been transformed into a system of non-dimensional differential equations which are solved numerically by Nachtsheim-Swigert iteration technique along with the sixth order Runge-Kutta integration scheme. The velocity, microrotation, temperature and concentration profiles are presented for different parameters. The present problem finds significant applications in hydromagnetic control of conducting polymeric sheets, magnetic materials processing, etc.展开更多
This paper deals with developing a numerical boundary layer flow model to analyze convective heat transfer characteristics of a micropolar fluid past a vertical plate in a composite material with viscous-Ohmic dissipa...This paper deals with developing a numerical boundary layer flow model to analyze convective heat transfer characteristics of a micropolar fluid past a vertical plate in a composite material with viscous-Ohmic dissipations in the presence of a transverse magnetic field.The basic governing equations are solved numerically by using the Runge-Kutta-Fehlberg method.The computed results reveal a reduction in the velocity,temperature,and microrotation profiles by increasing the Prandtl number.Also,the concentration distribution is enhanced by enhancing or decreasing Soret-Dufour parameter,and there seems to be decremented in the skin-friction coefficient values with Schmidt number.展开更多
To explore the coupled effect of heat and mass transfer,the coupled model of heat and mass transfer for a fixed bed adsorption process was established according to the Soret effect and the Dufour effect theory.Numeric...To explore the coupled effect of heat and mass transfer,the coupled model of heat and mass transfer for a fixed bed adsorption process was established according to the Soret effect and the Dufour effect theory.Numerical analysis methods were adopted to discuss the influences of heat transfer coefficients,mass transfer coefficients,and the coupled effect of heat and mass transfer on the fixed bed adsorption process respectively.Results have shown that heat transfer coefficients have little effect on mass transfer.To the degree of influence on the temperature field,the greatest is the heat transfer coefficient,followed by the axial thermal conductivity,the smallest is the external heat transfer coefficient.The mass transfer coefficients have some impact on the heat transfer and the mass transfer effect caused by the temperature gradient is more obvious than the heat transfer effect caused by the concentration gradient.展开更多
A porous medium involving endothermic chemical reaction was studied by using the irreversible flow processes thermodynamics method.A mathematical model describing the coupled irreversible processes of heat transfer,ma...A porous medium involving endothermic chemical reaction was studied by using the irreversible flow processes thermodynamics method.A mathematical model describing the coupled irreversible processes of heat transfer,mass transfer and chemical reaction in porous medium was established,and the model was solved numerically by applying the finite volume implicit method.By taking the decomposition of limestone as a case,the effects of the Soret and the Dufour phenomena were analyzed.The results showed that when the Peclet module was lower,the effects of the Soret and the Dufour phenomena could not be ignored.As a result,the product gas and the quantity of heat of gas in the porous medium would come through the reactor much quicker,and the concentration of the product gas,the temperature of gas flow and the solid conversion degree would be lower.展开更多
A comparative three-dimensional(3D)analysis for Casson-nanofluid and Carreau-nanofluid flows due to a flat body in a magnetohydrodynamic(MHD)stratified environment is presented.Flow is estimated to be suspended in a D...A comparative three-dimensional(3D)analysis for Casson-nanofluid and Carreau-nanofluid flows due to a flat body in a magnetohydrodynamic(MHD)stratified environment is presented.Flow is estimated to be suspended in a Darcy-Forchheimer medium.Soret and Dufour responses are also accommodated in the flow field.A moving(rotating)coordinate system is exercised to examine the bidirectionally stretched flow fields(flow,heat transfer,and mass transfer).Nanofluid is compounded by taking ethylene glycol/sodium alginate as base fluid and ferric-oxide(Fe3O4)as nanoparticles.Governing equations are handled by the application of optimal homotopy asymptotic method(OHAM),where convergence parameters are optimized through the classical least square procedure.The novel mechanism(hidden physics)due to appearing parameters is explored with the assistance of tabular and graphical expositions.Outcomes reveal the double behavior state for temperature field with thermal stratification/Dufour number,and for concentration field with Soret number due to the presence of turning points.展开更多
The present study is carried out to see the thermal-diffusion(Dufour) and diffusion-thermo(Soret) effects on the mixed convection boundary layer flow of viscoelastic nanofluid flow over a vertical stretching surface i...The present study is carried out to see the thermal-diffusion(Dufour) and diffusion-thermo(Soret) effects on the mixed convection boundary layer flow of viscoelastic nanofluid flow over a vertical stretching surface in a porous medium. Optimal homotopy analysis method(OHAM) is best candidate to handle highly nonlinear system of differential equations obtained from boundary layer partial differential equations via appropriate transformations. Graphical illustrations depicting different physical arising parameters against velocity, temperature and concentration distributions with required discussion have also been added. Numerically calculated values of skin friction coefficient, local Nusselt and Sherwood numbers are given in the form of table and well argued. It is found that nanofluid velocity increases with increase in mixed convective and viscoelastic parameters but it decreases with the increasing values of porosity parameter. Also, it is observed that Dufour number has opposite behavior on temperature and concentration profiles.展开更多
The aim of this study is to examine unsteady incompressible Magnetohydrodynamic fluid flow together with soret and dufour effects on mass and heat transfer through a collapsible elastic tube. The governing equations a...The aim of this study is to examine unsteady incompressible Magnetohydrodynamic fluid flow together with soret and dufour effects on mass and heat transfer through a collapsible elastic tube. The governing equations are continuity equation, momentum equation, energy equation and concentration equation. The velocity, temperature and concentration profiles together with heat and mass transfer rate were determined. The system of nonlinear partial differential equations governing the flow solved numerically by applying collocation method and implemented in MATLAB. The numerical solution of the profiles displayed both by graphically and numerically for different values of the physical parameters entering into the problem. The effects of varying various parameters such as Reynolds number, Hartmann number, Soret number, Dufour number and Prandtl number on velocity, temperature and concentration profiles also the rate of heat and mass transfer are discussed. The study is significant because heat and mass transfer mechanisms with the soret and dufour effects considerations play an important role due to its wide range of application including but not limited to medical fields, biological sciences and other physical sciences where collapsible tubes are applied.展开更多
对Soret和Dufour效应作用下的开口腔内双扩散自然对流进行了数值模拟。研究了在不同瑞利数 Ra(10 ^3≤Ra≤10^ 7)、刘易斯数Le(0.5≤Le≤8)、浮升力比 N(-5≤N≤5)、Soret数和Dufour数(0≤Sr=Df≤ 0.5 )下,开口正方腔内温度场、浓度场...对Soret和Dufour效应作用下的开口腔内双扩散自然对流进行了数值模拟。研究了在不同瑞利数 Ra(10 ^3≤Ra≤10^ 7)、刘易斯数Le(0.5≤Le≤8)、浮升力比 N(-5≤N≤5)、Soret数和Dufour数(0≤Sr=Df≤ 0.5 )下,开口正方腔内温度场、浓度场、流场的影响及平均努塞尔数 Nu 和平均舍伍德数 Sh 的变化。结果表明,当 N =-1时, Nu 和 Sh 都达到最小值,腔内传热、传质效果最弱。当Ra较小时,改变Le对 Nu 、 Sh 影响不大;当Ra不变时,增大Le使得 Nu 逐渐降低、 Sh 逐渐升高,腔内传质增强,传热被削弱。另外,Le=1时,Soret和Dufour效应的变化对开口方腔内传热传质影响并不明显。 Nu 和 Sh 随着Soret和Dufour效应影响增强而增大,与Sr、Df为0时对比,Sr、Df从0.1增大到0.5时, Nu 增加了10.4%到58.0%, Sh 增加了3.4%到13.1%。展开更多
A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory o...A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory of Soret and Dufour, a non-isothermal mathematical model was developed to simulate the PSA process. Effects of heat and mass transfer coefficients were studied. The coupled Soret and Dufour effects were also evaluated. It is found that the heat transfer coefficient has little effect on mass transfer in adsorption stage. However, it has some impacts in desorption stage. The maximum value of C/C0 increases by about 25% as heat transfer coefficient decreases. The temperature variation is less than 0.05 K with the change of mass transfer coefficient, so that the effect of mass transfer coefficient on heat transfer can be ignored. It is also concluded that the Soret and Dufour coupled effects are not obvious in pressure swing adsorption compared with fixed-bed adsorption.展开更多
文摘Combined effects of Soret(thermal-diffusion) and Dufour(diffusion-thermo) in MHD stagnation point flow by a permeable stretching cylinder were studied. Analysis was examined in the presence of heat generation/absorption and chemical reaction. The laws of conservation of mass, momentum, energy and concentration are found to lead to the mathematical development of the problem. Suitable transformations were used to convert the nonlinear partial differential equations into the ordinary differential equations. The series solutions of boundary layer equations through momentum, energy and concentration equations were obtained.Convergence of the developed series solutions was discussed via plots and numerical values. The behaviors of different physical parameters on the velocity components, temperature and concentration were obtained. Numerical values of Nusselt number, skin friction and Sherwood number with different parameters were computed and analyzed. It is found that Dufour and Soret numbers result in the enhancement of temperature and concentration distributions, respectively.
文摘This research explored the effects of an angled magnetic field, Brownian motion, and thermophoresis on the flow of an electrically conducting and chemically reacting Casson nanofluid under the influence of the Soret-Dufour mechanism. A set of partial differential equations is generated by the flow mode. The governing partial differential equations are solved numerically using the spectral collocation method after being transformed to self-similar forms. The effect of various fluid parameters on the velocity profile, temperature profile, and nanoparticle concentration is addressed. A quantitative agreement is observed when previous findings are compared to the current results. The skin friction, local Nusselt number, and local Sherwood number are also examined, and the results are presented in the table. This study discovered that the inclined magnetic field has a significant impact on the flow of the electrically conducting fluid by delaying its mobility within the boundary layer. The plastic dynamic viscosity, which acts as a barrier to fluid flow, is shown to degenerate the fluid velocity when the Casson parameter is increased. As a consequence, the findings may be used to improve thermal science instruments and increase industrial output.
文摘In this work, the Micropolar fluid flow and heat and mass transfer past a horizontal nonlinear stretching sheet through porous medium is studied including the Soret-Dufour effect in the presence of suction. A uniform magnetic field is applied transversely to the direction of the flow. The governing differential equations of the problem have been transformed into a system of non-dimensional differential equations which are solved numerically by Nachtsheim-Swigert iteration technique along with the sixth order Runge-Kutta integration scheme. The velocity, microrotation, temperature and concentration profiles are presented for different parameters. The present problem finds significant applications in hydromagnetic control of conducting polymeric sheets, magnetic materials processing, etc.
文摘This paper deals with developing a numerical boundary layer flow model to analyze convective heat transfer characteristics of a micropolar fluid past a vertical plate in a composite material with viscous-Ohmic dissipations in the presence of a transverse magnetic field.The basic governing equations are solved numerically by using the Runge-Kutta-Fehlberg method.The computed results reveal a reduction in the velocity,temperature,and microrotation profiles by increasing the Prandtl number.Also,the concentration distribution is enhanced by enhancing or decreasing Soret-Dufour parameter,and there seems to be decremented in the skin-friction coefficient values with Schmidt number.
文摘To explore the coupled effect of heat and mass transfer,the coupled model of heat and mass transfer for a fixed bed adsorption process was established according to the Soret effect and the Dufour effect theory.Numerical analysis methods were adopted to discuss the influences of heat transfer coefficients,mass transfer coefficients,and the coupled effect of heat and mass transfer on the fixed bed adsorption process respectively.Results have shown that heat transfer coefficients have little effect on mass transfer.To the degree of influence on the temperature field,the greatest is the heat transfer coefficient,followed by the axial thermal conductivity,the smallest is the external heat transfer coefficient.The mass transfer coefficients have some impact on the heat transfer and the mass transfer effect caused by the temperature gradient is more obvious than the heat transfer effect caused by the concentration gradient.
文摘A porous medium involving endothermic chemical reaction was studied by using the irreversible flow processes thermodynamics method.A mathematical model describing the coupled irreversible processes of heat transfer,mass transfer and chemical reaction in porous medium was established,and the model was solved numerically by applying the finite volume implicit method.By taking the decomposition of limestone as a case,the effects of the Soret and the Dufour phenomena were analyzed.The results showed that when the Peclet module was lower,the effects of the Soret and the Dufour phenomena could not be ignored.As a result,the product gas and the quantity of heat of gas in the porous medium would come through the reactor much quicker,and the concentration of the product gas,the temperature of gas flow and the solid conversion degree would be lower.
文摘A comparative three-dimensional(3D)analysis for Casson-nanofluid and Carreau-nanofluid flows due to a flat body in a magnetohydrodynamic(MHD)stratified environment is presented.Flow is estimated to be suspended in a Darcy-Forchheimer medium.Soret and Dufour responses are also accommodated in the flow field.A moving(rotating)coordinate system is exercised to examine the bidirectionally stretched flow fields(flow,heat transfer,and mass transfer).Nanofluid is compounded by taking ethylene glycol/sodium alginate as base fluid and ferric-oxide(Fe3O4)as nanoparticles.Governing equations are handled by the application of optimal homotopy asymptotic method(OHAM),where convergence parameters are optimized through the classical least square procedure.The novel mechanism(hidden physics)due to appearing parameters is explored with the assistance of tabular and graphical expositions.Outcomes reveal the double behavior state for temperature field with thermal stratification/Dufour number,and for concentration field with Soret number due to the presence of turning points.
文摘The present study is carried out to see the thermal-diffusion(Dufour) and diffusion-thermo(Soret) effects on the mixed convection boundary layer flow of viscoelastic nanofluid flow over a vertical stretching surface in a porous medium. Optimal homotopy analysis method(OHAM) is best candidate to handle highly nonlinear system of differential equations obtained from boundary layer partial differential equations via appropriate transformations. Graphical illustrations depicting different physical arising parameters against velocity, temperature and concentration distributions with required discussion have also been added. Numerically calculated values of skin friction coefficient, local Nusselt and Sherwood numbers are given in the form of table and well argued. It is found that nanofluid velocity increases with increase in mixed convective and viscoelastic parameters but it decreases with the increasing values of porosity parameter. Also, it is observed that Dufour number has opposite behavior on temperature and concentration profiles.
文摘The aim of this study is to examine unsteady incompressible Magnetohydrodynamic fluid flow together with soret and dufour effects on mass and heat transfer through a collapsible elastic tube. The governing equations are continuity equation, momentum equation, energy equation and concentration equation. The velocity, temperature and concentration profiles together with heat and mass transfer rate were determined. The system of nonlinear partial differential equations governing the flow solved numerically by applying collocation method and implemented in MATLAB. The numerical solution of the profiles displayed both by graphically and numerically for different values of the physical parameters entering into the problem. The effects of varying various parameters such as Reynolds number, Hartmann number, Soret number, Dufour number and Prandtl number on velocity, temperature and concentration profiles also the rate of heat and mass transfer are discussed. The study is significant because heat and mass transfer mechanisms with the soret and dufour effects considerations play an important role due to its wide range of application including but not limited to medical fields, biological sciences and other physical sciences where collapsible tubes are applied.
文摘对Soret和Dufour效应作用下的开口腔内双扩散自然对流进行了数值模拟。研究了在不同瑞利数 Ra(10 ^3≤Ra≤10^ 7)、刘易斯数Le(0.5≤Le≤8)、浮升力比 N(-5≤N≤5)、Soret数和Dufour数(0≤Sr=Df≤ 0.5 )下,开口正方腔内温度场、浓度场、流场的影响及平均努塞尔数 Nu 和平均舍伍德数 Sh 的变化。结果表明,当 N =-1时, Nu 和 Sh 都达到最小值,腔内传热、传质效果最弱。当Ra较小时,改变Le对 Nu 、 Sh 影响不大;当Ra不变时,增大Le使得 Nu 逐渐降低、 Sh 逐渐升高,腔内传质增强,传热被削弱。另外,Le=1时,Soret和Dufour效应的变化对开口方腔内传热传质影响并不明显。 Nu 和 Sh 随着Soret和Dufour效应影响增强而增大,与Sr、Df为0时对比,Sr、Df从0.1增大到0.5时, Nu 增加了10.4%到58.0%, Sh 增加了3.4%到13.1%。
基金Projects(20976200,20676154) supported by the National Natural Science Foundation of China
文摘A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory of Soret and Dufour, a non-isothermal mathematical model was developed to simulate the PSA process. Effects of heat and mass transfer coefficients were studied. The coupled Soret and Dufour effects were also evaluated. It is found that the heat transfer coefficient has little effect on mass transfer in adsorption stage. However, it has some impacts in desorption stage. The maximum value of C/C0 increases by about 25% as heat transfer coefficient decreases. The temperature variation is less than 0.05 K with the change of mass transfer coefficient, so that the effect of mass transfer coefficient on heat transfer can be ignored. It is also concluded that the Soret and Dufour coupled effects are not obvious in pressure swing adsorption compared with fixed-bed adsorption.
