Thermal Stratification Parameter Research Articles

Double stratified radiative Jeffery magneto nanofluid flow along an inclined stretched cylinder with chemical reaction and slip condition

A mathematical model is designed to deliberate the flow of an MHD Jeffery nanofluid past a vertically inclined stretched cylinder near a stagnation point. The flow analysis is performed in attendance of thermal radiation, mixed convection and chemical reaction. Influence of thermal and solutal stratification with slip boundary condition is also considered. Apposite transformations are engaged to convert the nonlinear partial differential equations to differential equations with high nonlinearity. Convergent series solutions of the problem are established via the renowned Homotopy Analysis Method (HAM). Graphical illustrations are plotted to depict the effects of prominent arising parameters against all involved distributions. Numerically erected tables of important physical parameters like Skin friction, Nusselt and Sherwood numbers are also give. Comparative studies (with a previously examined work) are also included to endorse our results. It is noticed that the thermal stratification parameter has diminishing effect on temperature distribution. Moreover, the velocity field is a snowballing and declining function of curvature and slip parameters respectively.

Double Stratification in Flow by Curved Stretching Sheet With Thermal Radiation and Joule Heating

Magnetohydrodynamic (MHD) flow of viscous fluid by curved stretching surface is presented in this paper. Heat and mass transfer analysis is studied with double stratification and thermal radiation effects. Joule heating is also taken into consideration. Basic equations of flow problem are obtained using curvilinear coordinates. The partial differential equations are reduced to the nonlinear ordinary differential equations using suitable transformations. Graphical results are shown and analyzed for the effect of different parameters on fluid characteristics. It is noted that thermal and solutal stratification parameters have opposite effect on temperature and concentration distributions. Magnitude of pressure, skin friction coefficient, and Nusselt number decreases for larger curvature parameter.

Transport of magnetohydrodynamic nanomaterial in a stratified medium considering gyrotactic microorganisms

Impact of gyrotactic microorganisms on two-dimensional (2D) stratified flow of an Oldroyd-B nanomaterial is highlighted. Applied magnetic field along with mixed convection is considered in the formulation. Theory of microorganisms is utilized just to stabilize the suspended nanoparticles through bioconvection induced by combined effects of buoyancy forces and magnetic field. Convergent series solutions for the obtained nonlinear differential systems are derived. Impacts of different emerging parameters on velocity, temperature, concentration, motile microorganisms density, density number of motile microorganisms and local Nusselt and Sherwood numbers are graphically addressed. It is observed that thermal, concentration and motile density stratification parameters result in reduction of temperature, concentration and motile microorganisms density distributions respectively.

Numerical investigation of coupled natural convection and radiation in a differentially heated cubic cavity filled with humid air. Effects of the cavity size

ABSTRACTA numerical study of natural convection with surface and air/H2O mixture radiation in a differentially heated cubic square cavity is presented. The coupled flow and heat transfers in the cavity are predicted by coupling a finite volume method with a spectral line weighted sum of gray gase model to describe gas radiative properties. The radiative transfer equation is solved by means of the discrete ordinate method. Simulations are performed at Ra = 106, considering different combinations of passive wall and/or gas radiation properties and different cavity length. It was found that in presence of a participative medium representative of building, cavity length has a strong influence on temperature and velocity fields which affect the global circulation and heat transfers in the cavity. For each steady-state solution, the convective and radiative contributions to the global heat transfer are discussed. More specifically, boundary layer thickness, thermal stratification parameter, and three-dimensional effects are compared to pure convective case results. The results suggest that radiative effects, often considered as negligible in view of the relatively low optical thickness, may not be neglected when trying to predict regime transitions.

Effects of atmospheric cold fronts on stratification and water quality of a tropical reservoir: implications for aquaculture

Stratification and mixing patterns of a water body are influenced by the variability of atmospheric systems, which can also modify their biogeochemical properties. The primary goal of this study was to analyze the effect of atmospheric cold fronts (CFs) on thermal stratification and water quality parameters in 4 embayments of the Furnas Hydroelectric Reservoir (FHR) (southeastern Brazil), a warm monomictic water body. A secondary goal was to evaluate the implications of this effect on the aquaculture of Nile tilapia Oreochromis niloticus (L.) in net cages. A 2 yr dataset of meteorological and water quality parameters was used to compute heat flux balance components and buoyancy frequency. These parameters were used to evaluate the influence of CFs on FHR water column stability and water quality. It was observed that the passing of CFs increased net heat loss and wind velocity, resulting in a partial mixture of surface waters with deeper layers. These changes in the physical structure of the water column altered the diel cycle of water temperature, led to a slight decrease in dissolved oxygen concentrations and pH values during the stratification period, and contributed to the increase in dilution power at the fish cultivation sites. However, following CF passages, no significant changes were observed in water quality parameters that influenced Nile tilapia cultivation in the FHR. Nevertheless, the understanding of meteorological systems and their influence on the physical and biogeochemical properties of an aquatic system is important for optimal management of aquaculture activities.

Numerical study of a thermally stratified flow of a tangent hyperbolic fluid induced by a stretching cylindrical surface

The effects of temperature stratification on a tangent hyperbolic fluid flow over a stretching cylindrical surface are studied. The fluid flow is achieved by taking the no-slip condition into account. The mathematical modelling of the physical problem yields a nonlinear set of partial differential equations. These obtained partial differential equations are converted in terms of ordinary differential equations. Numerical investigation is done to identify the effects of the involved physical parameters on the dimensionless velocity and temperature profiles. In the presence of temperature stratification it is noticed that the curvature parameter makes both the fluid velocity and fluid temperature increase. In addition, positive variations in the thermal stratification parameter produce retardation with respect to the fluid flow, as a result the fluid temperature drops. The skin friction coefficient shows a decreasing nature for increasing value of both power law index and Weissenberg number, whereas the local Nusselt number is an increasing function of the Prandtl number, but opposite trends are found with respect to the thermal stratification parameter. The obtained results are validated by making a comparison with the existing literature which brings support to the presently developed model.

Entropy generation due to mixed convection over vertical permeable cylinders using nanofluids

This paper discusses the thermal stratification and suction/injection effects on the entropy generation and heat transfer due to convective boundary layer flow over a vertical stretching cylinder using Buongiorno’s model for nanofluids. For the nanoparticle volume fraction, the boundary conditions are taken such that its normal fluxes are zero. The governing equations and the entropy equation are derived in cylindrical coordinates, in details. Similar transformations are used to convert the governing equation into ordinary differential equations and the resulting system is solved numerically using MATLAB function bvp4c. The obtained results are presented in terms of velocity profiles, temperature distributions, nanoparticle volume fraction, local entropy generation, skin friction coefficient and local Nusselt number. It is found that the minimum values of the entropy generation occur in the injection case, while the suction case maximizes the entropy generation. The increase in the thermal stratification parameter decreases the profiles of velocity temperature and nanoparticle volume fraction, while it enhances the entropy generation.

Thermophysical aspects of stagnation point magnetonanofluid flow yields by an inclined stretching cylindrical surface: a non-Newtonian fluid model

In various attempts, researchers considered Eyring–Powell fluid flow past a flat stretching surface supported with different physical effects, but as yet few explorations are proposed with accuracy regarding cylindrical stretching surface. In this work, we have considered magnetohydrodynamic Eyring–Powell nanofluid flow brought by an included stretching cylindrical surface under the region of stagnation point. To report thermophysical aspects, Joule heating, thermal radiations, mixed convection, temperature stratification, and heat generation effects are taken into account. The flow conducting differential equations are fairly converted into system of coupled non-linear ordinary differential equations by means of appropriate transformation. A numerical communication is made against these obtained coupled equations through shooting method supported with fifth-order Runge–Kutta scheme. It is found that fluid temperature shows an inciting nature towards Eckert number, thermophoresis parameter, Brownian motion parameter, thermal radiation parameter, and heat generation parameter, but it reflects opposite trends for Lewis number and thermal stratification parameter. Furthermore, the obtained results are validated by providing comparison with existing values which set a benchmark of quality of computational algorithm.

Mutual effects of thermal radiations and thermal stratification on tangent hyperbolic fluid flow yields by both cylindrical and flat surfaces

The characteristics of tangent hyperbolic fluid flow in the presence of both thermal radiation and thermal stratification effects are not discussed until now especially by way of an inclined cylindrical surface. Therefore, an endeavour as a comparative study is reported to offered numerical solution for tangent hyperbolic fluid model towards both cylindrical and flat stretching surfaces. The physical situation which also includes the noteworthy effects namely, stagnation point region, mixed convection, magnetic field individualities and heat generation is translated in terms of partial differential equations and for solution purpose a computational algorithm is executed. The obtained results are provided by way of both graphical and tabular outcomes. It is observed that the temperature profile is an increasing function of thermal radiation parameter but opposite trends are noticed for positive values of thermal stratification parameter. In addition, straight line approximation is accomplished to scrutinize the impact of mixed convection and an inclination effects on skin friction coefficient while the impact of thermal radiation and thermal stratification parameters are provided on heat transfer rate.

Effects of thermal and solutal stratification on jeffrey magneto-nanofluid along an inclined stretching cylinder with thermal radiation and heat generation/absorption

A mathematical model is established to discuss the flow of magneto Jeffrey nanofluid with heat generation/absorption and thermal radiation past an inclined stretched cylinder. Effects of thermal and concentration stratification are also taken into account. Analytical solution of the problem is obtained using Homotopy analysis method. Graphical illustrations depicting effects of prominent arising parameters on involved profiles with requisite discussion are also presented. Further, numerical data representing Skin friction, heat and mass transfer rates are also given in the form of table. A comparison in limiting case to previous study is also added to verify our results. It is found that temperature and concentration distributions are decreasing functions of thermal and solutal stratification parameters respectively.

Behavior of stratification phenomenon in flow of Maxwell nanomaterial with motile gyrotactic microorganisms in the presence of magnetic field

The ultimate purpose of present article is to investigate the heat, mass and motile microorganisms transfer rates in the convective stretched flow of Maxwell fluid consisting of nanoparticles and gyrotactic microorganisms. Magneto nanofluid in presence of mixed convection and stratification is considered. Concept of microorganisms is utilized just to stabilize the suspended nanoparticles through bioconvection which has been induced by combined effects of buoyancy forces and magnetic field. Further interesting aspects of Brownian motion, thermophoresis and stratification are examined. Convergent series solutions for the obtained nonlinear differential systems are derived. Impacts of different emerging parameters on velocity, temperature, concentration and motile microorganisms density are addressed through graphs. Numerical values for the local Nusselt, Sherwood and density number of motile microorganisms are computed and analyzed. It is observed that thermal, concentration and motile density stratification parameters result in the reduction of temperature, concentration and motile microorganisms density distributions, respectively.

Magnetohydrodynamic (MHD) flow of nanofluid with double stratification and slip conditions

ABSTRACTThis paper concerns with the analysis of double stratification in magnetohydrodynamic (MHD) flow of nanofluid by a stretching cylinder. Brownian motion and thermophoresis effects are present in the transport equations. The flow is subjected to velocity, thermal and solutal slip conditions. Non-linear ordinary differential equations are obtained from the governing non-linear partial differential equations after using appropriate transformations. The resulting non-linear ordinary differential equations are solved for the convergent series solutions. The velocity, temperature and concentration profiles are illustrated for different emerging parameters. Velocity distribution decays for higher estimation of velocity slip parameter. Furthermore, temperature decreases and concentration enhances for higher values of thermal stratification parameter and thermophoresis parameter, respectively. Numerical results for the skin friction, Nusselt number and Sherwood number are also presented and examined. Comparison between the published limiting solutions and present results is found in an excellent agreement.

Numerical communication for MHD thermally stratified dual convection flow of Casson fluid yields by stretching cylinder

This work reports the comparative study of magnetohydrodynamic mixed convection boundary layer flow of Casson fluid brought by both flat and cylindrical stretching surfaces. Flow field analysis is accounted with thermal stratification phenomena. The temperature is assumed to be higher across the surface of cylinder as compared to ambient fluid. The arising mathematically modelled partial differential equations of Casson fluid flow are successfully converted into ordinary differential equations with the source of suitable transformation. The numerical solutions are computed through the application of shooting technique charted with fifth order Runge-Kutta algorithm. The effect logs of an interesting physical parameters namely, magnetic field parameter, mixed convection parameter, thermal stratification parameter, heat generation parameter, curvature parameter and Prandtl number are discussed graphically. Further, the variations of skin friction coefficient and heat transfer rate are identified by way of tables.

Non-similarity Solutions for Natural Convective Flow of a Nanofluid Over Vertical Frustum of a Cone Embedded in a Doubly Stratified Non-Darcy Porous Medium

The present study emphasize the effects of stable thermal and solutal stratification on natural convective heat and mass transfer flow of a nanofluid over vertical frustum of a cone embedded in a non-Darcy porous medium. To attain physically acceptable results, the zero nanoparticle flux condition is considered at the surface of frustum of a cone rather than the wall condition. Initially, suitable non-similar transformations are used to convert the governing complex flow equations into non-dimensional form and then solved numerically by using a newly introduced spectral method named as bivariate pseudo-spectral local linearisation method. To test the accuracy of present method, the convergence test and error analysis are conducted. The Buongiorno’s nanofluid model which incorporates the effects of thermophoresis and Brownian motion is used in the present analysis. The effects of non-Darcy parameter, Lewis number, thermal and solutal stratification parameters on the velocity, temperature, nanoparticle volume fraction and regular concentration as well as the skin friction, Nusselt number, nanoparticle and regular Sherwood numbers are studied.

Parabolic curve fitting study subject to Joule heating in MHD thermally stratified mixed convection stagnation point flow of Eyring-Powell fluid induced by an inclined cylindrical surface

The current analysis is carried out to envision the properties of magneto-hydrodynamic boundary layer stagnation point flow of Eyring-Powell (non-Newtonian) fluid induced by an inclined stretching cylindrical surface in the presence of both mixed convection and Joule heating effects. Flow analysis is manifested with temperature stratification phenomena. The strength of temperature adjacent to the cylindrical surface is assumed to be higher in strength as compared to the ambient fluid. A suitable similarity transformations are utilized to convert the flow conducting equations (mathematically modelled) into system of coupled non-linear ordinary differential equations. A fifth order Runge-Kutta algorithm charted with shooting scheme is used to trace out the numerical additions. It was found that the velocity profile is an increasing function of both mixed convection and curvature parameters. Temperature profile show inciting nature towards Eckert number. In addition, a straight line and parabolic curve fitting way of study is executed to inspect the effect logs of mixed convection parameter, magnetic field parameter, thermal stratification parameter and heat generation parameter on skin friction coefficient and heat rate. It seems to be first attempt in this direction and will serve as a facilitating source for the preceding studies regarding fluid rheology.

Double stratification in the MHD flow of a nanofluid due to a rotating disk with variable thickness

In this article the MHD flow of a nanofluid is examined due to a variable-thickness rotating disk. Heat and mass transfer analysis is done by utilizing the effects of thermal and solutal stratification. Governing partial differential equations are simplified by applying boundary layer approximation. The resulting equations are further converted to ordinary differential equations by making suitable deformations. How various physical parameters are influencing velocities, temperature, concentration, heat transfer rate and surface drag force is examined briefly. Behavior of these relevant parameters is presented graphically to make a comprehensive discussion of results. Axial and radial velocities are increasing for larger exponent of the power law fluid. Temperature is a decreasing function of the Prandtl number while it causes an increase in the heat transfer rate. Increasing values of thermal stratification and solutal stratification parameters result in the reduction of temperature and concentration, respectively.

Application of shooting method on MHD thermally stratified mixed convection flow of non-Newtonian fluid over an inclined stretching cylinder

An analysis is made to examine the magnetohydrodynamic mixed convection boundary layer flow of Eyring-Powell fluid brought by an inclined stretching cylinder. Flow field analysis is accounted by thermal stratification phenomena. The temperature is assumed to be higher across the surface of cylinder as compared to ambient fluid. The arising mathematical model regarding Eyring-Powell fluid is governed by interesting physical parameters which includes mixed convection parameter, thermal stratification parameter, heat generation/absorption parameter, curvature parameter, fluid parameters, magnetic field parameter and Prandtl number. The numerical solutions are computed through the application of shooting technique conjunction with fifth order Runge-Kutta algorithm. In addition, numeric values for two unlike geometries namely, plate and cylinder for skin friction coefficient and Nusselt number are presented with the aid graphs and some particular cases are discussed. The present study is validated by establishing comparison with previously published works, which sets a benchmark of quality of shooting method.

UCM flow across a melting surface in the presence of double stratification and cross-diffusion effects

Abstract In this article, we analyzed the upper convected Maxwell fluid (UCM) flow across a horizontal melting surface in the presence of cross-diffusion and double stratification (thermal and solutal) effects. We reconstructed the controlling equations as a group of nonlinear ordinary differential equations and then resolved by enforcing Runge-Kutta method with shooting technique. The influence of important parameters on the three common profiles (velocity, temperature, and concentration) is discussed through plots. Tables are utilized to discuss the wall friction, heat and mass transfer rates of both Newtonian and UCM flows. We witnessed that the thermal stratification, Soret number, Schmidt number and temperature dependent viscous parameter improve heat transfer rate. Setting the two flows side by side, it is worthy to mention that the temperature and concentration profiles looking high in the Newtonian fluid flow.

Numerical study of double stratification in Casson fluid flow in the presence of mixed convection and chemical reaction

In this article, mixed convection MHD Casson fluid flow towards an inclined stretching cylindrical surface in a double stratified medium is considered. The flow field situation is manifested with heat generation/absorption and chemical reaction effects. The flow narrating partial differential equations are converted in terms of ordinary differential equations by means of suitable transformation. A computational algorithm (shooting method along with Runge-Kutta scheme) is executed to offered numerical solution. The effects of an involved flow controlling parameters namely curvature parameter, mixed convection parameter, an inclination, magnetic field parameter, thermal stratification parameter, heat generation/absorption parameter, solutal stratification parameter and chemical reaction parameter are offered with the aid of graphs and tables. It is noticed that both Casson fluid temperature and Casson fluid concentration admits decline nature towards thermal stratification parameter and solutal stratification parameter respectively. In addition, the justification of present outcomes is obtained by developing comparison with existing published work. We found an excellent match which yields the surety of numerical results subject to Casson fluid flow brought by an inclined stretching cylindrical surface immersed in a double stratified medium.

Temperature and concentration stratification effects on non-Newtonian fluid flow past a cylindrical surface

The theme of present work is to report the numerical solution of mixed convection tangent hyperbolic fluid flow towards stretching cylindrical surface immersed in a double stratified media. The fluid flow is attained through no slip condition. The flow regime characteristics are modelled in terms of partial differential equations. A similarity transformation is used to transform partial differential equations into coupled non-linear ordinary differential equations. A computational algorithm is executed to predict numerical results. The effects of flow controlling parameters namely, mixed convection parameter, thermal stratification and solutal stratification parameters on velocity, temperature and concentration are examined and offered by means of graphical outcomes. It is noticed that in the presence of mixed convection effect both the fluid temperature and concentration are decreasing function of thermal stratification and solutal stratification parameters respectively. The obtained values are certified by developing comparison with existing values and an excellent agreement is observed which confirms the execution of computational algorithm.