This paper presents the study of convective heat and mass transfer characteristics of an incompressible MHD visco-elastic fluid flow immersed in a porous medium over a stretching sheet with chemical reaction and therm...This paper presents the study of convective heat and mass transfer characteristics of an incompressible MHD visco-elastic fluid flow immersed in a porous medium over a stretching sheet with chemical reaction and thermal stratification effects. The resultant governing boundary layer equations are highly non-linear and coupled form of partial differential equations, and they have been solved by using fourth order Runge-Kutta integration scheme with Newton Raphson shooting method. Numerical computations are carried out for the non-dimensional physical parameters. Here a numerical has been carried out to study the effect of different physical parameters such as visco-elasticity, permeability of the porous medium, magnetic field, Grashof number, Schmidt number, heat source parameter and chemical reaction parameter on the flow, heat and mass transfer characteristics.展开更多
The problem of magneto-hydro-dynamic (MHD) mass and heat transfer of an oscillatory fluid in two-dimensional viscous, electrically conducting over an infinite vertical permeable moving plate in a saturated porous medi...The problem of magneto-hydro-dynamic (MHD) mass and heat transfer of an oscillatory fluid in two-dimensional viscous, electrically conducting over an infinite vertical permeable moving plate in a saturated porous medium with the presence of a transverse magnetic field and chemical reaction is analytically presented. The governing equations, momentum, energy, and concentration are solved. Various flow parameters effects on velocity, temperature and concentration fields are discussed. It is found that, the fluid velocity increases with increasing both the permeability and chemical reaction parameters. While, it increases with decreasing the magnetic field parameter. Furthermore, the concentration increases with increasing chemical reaction parameters.展开更多
We investigate heat and mass transfer in an isosceles trapezoidal cavity, filled with charcoal considered as a granular porous medium. The Darcy-Brinkman-Forchheimer flow model is coupled to the energy and mass equati...We investigate heat and mass transfer in an isosceles trapezoidal cavity, filled with charcoal considered as a granular porous medium. The Darcy-Brinkman-Forchheimer flow model is coupled to the energy and mass equations with the assumption of non-thermal equilibrium. These equations are discretized by the finite volume method with an offset mesh and then solved by the line-by-line method of Thomas. The coupling between pressure and velocity is obtained by Semi-Implicit Method for Pressure Linked Equations. (SIMPLE) algorithm. The results show that the temperature in the cavity increases when the inclination angle of the sides walls decreases. The 15° inclination is selected as being able to offer better thermal performance in the cookstove combustion chamber.展开更多
The in-medium quark condensate is studied with an equivalent-mass approach in which one does not need to make assumptions on the derivatives of model parameters with respect to the quark current mass.It is shown that ...The in-medium quark condensate is studied with an equivalent-mass approach in which one does not need to make assumptions on the derivatives of model parameters with respect to the quark current mass.It is shown that the condensate is generally a decreasing function of both the density and temperature with the decreasing speed depending on the confinement parameter.Specially,at given density,the condensate decreases on increasing temperature.The decreasing speed is comparatively small at lower temperature,and becomes very fast at higher temperature.展开更多
A three-porous-medium model for transvascular exchange and extravascular transport of fluid and macromolecules in a spherical solid tumor is developed. The microvasculature , lymphatics, and tissue space are each trea...A three-porous-medium model for transvascular exchange and extravascular transport of fluid and macromolecules in a spherical solid tumor is developed. The microvasculature , lymphatics, and tissue space are each treated as a porous medium with the flow of blood. lymph, and interstitial fluid obeying Darcy's law and Starling 's assumption. In this part, the role of interstitial pressure and fluid convection are studited. The analytical soiutions are obtained for foe isolated tumor and the normal-tissue-surrounded tumor respectively. The calculated interstitial pressure profue are consistent with the experimental observation that the elevated interstitial pressure is a major barrier in the penetration of macromolecular drug into tumors. The factors which may reduce the interstitial pressure are analyzed in details.展开更多
A numerical study on boundary layer flow behaviour, heat and mass transfer characteristics of a nanofluid over an exponentially stretching sheet in a porous medium is presented in this paper. The sheet is assumed to b...A numerical study on boundary layer flow behaviour, heat and mass transfer characteristics of a nanofluid over an exponentially stretching sheet in a porous medium is presented in this paper. The sheet is assumed to be permeable. The governing partial differential equations are transformed into coupled nonlinear ordinary differential equations by using suitable similarity transformations. The transformed equations are then solved numerically using the well known explicit finite difference scheme known as the Keller Box method. A detailed parametric study is performed to access the influence of the physical parameters on longitudinal velocity, temperature and nanoparticle volume fraction profiles as well as the local skin-friction coefficient, local Nusselt number and the local Sherwood number and then, the results are presented in both graphical and tabular forms.展开更多
In this work, the peristaltic motion of a nano non-Newtonian fluid which obeys Carreau model through a porous medium inside an asymmetric channel is investigated. The hall current effects with Joule heating and viscou...In this work, the peristaltic motion of a nano non-Newtonian fluid which obeys Carreau model through a porous medium inside an asymmetric channel is investigated. The hall current effects with Joule heating and viscous dissipation are considered. The problem is modulated mathematically by a set of nonlinear partial differential equations which describe the conservation of mass, momentum, energy and concentration of nanoparticles. The non-dimensional form of these equations is simplified under the assumption of long wavelength and low Reynolds number, and then resulting equations of coupled nonlinear differential equations are tackled numerically with appropriate boundary conditions. Graphical results are presented for dimensionless velocity, temperature, concentration and pressure gradient in order to illustrate the variations of various parameters of this problem on these obtained solutions.展开更多
The objective of the present study is to investigate diffusion-thermo (Dufour effect) and radiation effects on unsteady MHD free convection flow past an impulsively started infinite vertical plate with variable temper...The objective of the present study is to investigate diffusion-thermo (Dufour effect) and radiation effects on unsteady MHD free convection flow past an impulsively started infinite vertical plate with variable temperature and uniform mass diffusion in the presence of transverse applied magnetic field through porous medium. At time t > 0, the plate is given an impulsive motion with constant velocity in the vertical upward direction against to the gravitational field. At the same time the plate temperature is raised linearly with time t and the level of concentration near the plate is raised to . A magnetic field of uniform strength is applied normal to the direction to the flow. The dimen- sionless governing equations are solved in closed form by Laplace-transform technique. The effect of flow parameters on velocity, temperature, concentration, the rate of heat transfer and the rate of mass transfer are shown through graphs.展开更多
Recently, people suffer from the inability to maintain weight with an increasing body mass, and this may be due to several reasons, including the type and quantity of food. In current study, the effect of the glycemic...Recently, people suffer from the inability to maintain weight with an increasing body mass, and this may be due to several reasons, including the type and quantity of food. In current study, the effect of the glycemic index of foods (high-low-medium) on the speed of return of hunger in adult women was discussed. Non-pregnant or lactating women who do not suffer from chronic diseases such as diabetes and pressure, for three days in a row for breakfast, lunch, and dinner, by calculating the number of hours preceding the feeling of hunger, as the results showed that the least hours of hunger were after eating foods with a low glycemic index and then followed by foods with a medium glycemic index, and the number of hours of starvation after eating foods with a high glycemic index was the least, and this leads to an increase in subsequent food intake and an increase in calories during the day. The results indicated: first day that are high in the glycemic index (breakfast). Highest percentage of feeling hungry was 30% after 4 h (lunch). The highest percentage of feeling hungry was 30% after 3 h, (dinner), the highest percentage of not feeling hungry by 50%. The second day with a low glycemic index (breakfast). The highest percentage of feeling hungry after 4 h was 30%, (lunch). The highest percentage of feeling hungry after 4 h was 30%, (dinner). The highest percentage of not feeling hungry was 80%. Third day with a medium glycemic index (breakfast). The highest percentage of feeling hungry was after 3 h and 4 h, with a percentage of 30%, (lunch), the highest percentage of feeling hungry after 4 h, with a percentage of 30%, (dinner), the highest percentage of not feeling hungry by 70%, which increases body mass and weight continuously, and this leads to an increase in vulnerability to chronic diseases. Therefore, it is important to preserve and be careful to eat meals with a low and medium glycemic index in the diets, with the addition of foods with a high glycemic index, without negligence or excess, and we look forward to increasing the research on the effect of the glycemic index of food on the speed of return of hunger while standardizing the quantity and type of food for all volunteers.展开更多
文摘This paper presents the study of convective heat and mass transfer characteristics of an incompressible MHD visco-elastic fluid flow immersed in a porous medium over a stretching sheet with chemical reaction and thermal stratification effects. The resultant governing boundary layer equations are highly non-linear and coupled form of partial differential equations, and they have been solved by using fourth order Runge-Kutta integration scheme with Newton Raphson shooting method. Numerical computations are carried out for the non-dimensional physical parameters. Here a numerical has been carried out to study the effect of different physical parameters such as visco-elasticity, permeability of the porous medium, magnetic field, Grashof number, Schmidt number, heat source parameter and chemical reaction parameter on the flow, heat and mass transfer characteristics.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10247004, 10565001, and the Natural Science Foundation of Guangxi Province of China undcr Grant Nos. 0481030, 0575020, and 0542042
文摘The problem of magneto-hydro-dynamic (MHD) mass and heat transfer of an oscillatory fluid in two-dimensional viscous, electrically conducting over an infinite vertical permeable moving plate in a saturated porous medium with the presence of a transverse magnetic field and chemical reaction is analytically presented. The governing equations, momentum, energy, and concentration are solved. Various flow parameters effects on velocity, temperature and concentration fields are discussed. It is found that, the fluid velocity increases with increasing both the permeability and chemical reaction parameters. While, it increases with decreasing the magnetic field parameter. Furthermore, the concentration increases with increasing chemical reaction parameters.
文摘We investigate heat and mass transfer in an isosceles trapezoidal cavity, filled with charcoal considered as a granular porous medium. The Darcy-Brinkman-Forchheimer flow model is coupled to the energy and mass equations with the assumption of non-thermal equilibrium. These equations are discretized by the finite volume method with an offset mesh and then solved by the line-by-line method of Thomas. The coupling between pressure and velocity is obtained by Semi-Implicit Method for Pressure Linked Equations. (SIMPLE) algorithm. The results show that the temperature in the cavity increases when the inclination angle of the sides walls decreases. The 15° inclination is selected as being able to offer better thermal performance in the cookstove combustion chamber.
基金Supported by National Natural Science Foundation of China under Grant Nos.11045006 and 11135011the Key Project from Chinese Academy of Sciences(12A0A0012)the President Foundation by the Graduate University of Chinese Academy of Sciences
文摘The in-medium quark condensate is studied with an equivalent-mass approach in which one does not need to make assumptions on the derivatives of model parameters with respect to the quark current mass.It is shown that the condensate is generally a decreasing function of both the density and temperature with the decreasing speed depending on the confinement parameter.Specially,at given density,the condensate decreases on increasing temperature.The decreasing speed is comparatively small at lower temperature,and becomes very fast at higher temperature.
文摘A three-porous-medium model for transvascular exchange and extravascular transport of fluid and macromolecules in a spherical solid tumor is developed. The microvasculature , lymphatics, and tissue space are each treated as a porous medium with the flow of blood. lymph, and interstitial fluid obeying Darcy's law and Starling 's assumption. In this part, the role of interstitial pressure and fluid convection are studited. The analytical soiutions are obtained for foe isolated tumor and the normal-tissue-surrounded tumor respectively. The calculated interstitial pressure profue are consistent with the experimental observation that the elevated interstitial pressure is a major barrier in the penetration of macromolecular drug into tumors. The factors which may reduce the interstitial pressure are analyzed in details.
文摘A numerical study on boundary layer flow behaviour, heat and mass transfer characteristics of a nanofluid over an exponentially stretching sheet in a porous medium is presented in this paper. The sheet is assumed to be permeable. The governing partial differential equations are transformed into coupled nonlinear ordinary differential equations by using suitable similarity transformations. The transformed equations are then solved numerically using the well known explicit finite difference scheme known as the Keller Box method. A detailed parametric study is performed to access the influence of the physical parameters on longitudinal velocity, temperature and nanoparticle volume fraction profiles as well as the local skin-friction coefficient, local Nusselt number and the local Sherwood number and then, the results are presented in both graphical and tabular forms.
文摘In this work, the peristaltic motion of a nano non-Newtonian fluid which obeys Carreau model through a porous medium inside an asymmetric channel is investigated. The hall current effects with Joule heating and viscous dissipation are considered. The problem is modulated mathematically by a set of nonlinear partial differential equations which describe the conservation of mass, momentum, energy and concentration of nanoparticles. The non-dimensional form of these equations is simplified under the assumption of long wavelength and low Reynolds number, and then resulting equations of coupled nonlinear differential equations are tackled numerically with appropriate boundary conditions. Graphical results are presented for dimensionless velocity, temperature, concentration and pressure gradient in order to illustrate the variations of various parameters of this problem on these obtained solutions.
文摘The objective of the present study is to investigate diffusion-thermo (Dufour effect) and radiation effects on unsteady MHD free convection flow past an impulsively started infinite vertical plate with variable temperature and uniform mass diffusion in the presence of transverse applied magnetic field through porous medium. At time t > 0, the plate is given an impulsive motion with constant velocity in the vertical upward direction against to the gravitational field. At the same time the plate temperature is raised linearly with time t and the level of concentration near the plate is raised to . A magnetic field of uniform strength is applied normal to the direction to the flow. The dimen- sionless governing equations are solved in closed form by Laplace-transform technique. The effect of flow parameters on velocity, temperature, concentration, the rate of heat transfer and the rate of mass transfer are shown through graphs.
文摘Recently, people suffer from the inability to maintain weight with an increasing body mass, and this may be due to several reasons, including the type and quantity of food. In current study, the effect of the glycemic index of foods (high-low-medium) on the speed of return of hunger in adult women was discussed. Non-pregnant or lactating women who do not suffer from chronic diseases such as diabetes and pressure, for three days in a row for breakfast, lunch, and dinner, by calculating the number of hours preceding the feeling of hunger, as the results showed that the least hours of hunger were after eating foods with a low glycemic index and then followed by foods with a medium glycemic index, and the number of hours of starvation after eating foods with a high glycemic index was the least, and this leads to an increase in subsequent food intake and an increase in calories during the day. The results indicated: first day that are high in the glycemic index (breakfast). Highest percentage of feeling hungry was 30% after 4 h (lunch). The highest percentage of feeling hungry was 30% after 3 h, (dinner), the highest percentage of not feeling hungry by 50%. The second day with a low glycemic index (breakfast). The highest percentage of feeling hungry after 4 h was 30%, (lunch). The highest percentage of feeling hungry after 4 h was 30%, (dinner). The highest percentage of not feeling hungry was 80%. Third day with a medium glycemic index (breakfast). The highest percentage of feeling hungry was after 3 h and 4 h, with a percentage of 30%, (lunch), the highest percentage of feeling hungry after 4 h, with a percentage of 30%, (dinner), the highest percentage of not feeling hungry by 70%, which increases body mass and weight continuously, and this leads to an increase in vulnerability to chronic diseases. Therefore, it is important to preserve and be careful to eat meals with a low and medium glycemic index in the diets, with the addition of foods with a high glycemic index, without negligence or excess, and we look forward to increasing the research on the effect of the glycemic index of food on the speed of return of hunger while standardizing the quantity and type of food for all volunteers.
