A similarity solution for the steady hydromagnetic convective heat and mass transfer with slip flow from a spinning disk with viscous dissipation and Ohmic heating yields a system of non-linear, coupled, ordinary diff...A similarity solution for the steady hydromagnetic convective heat and mass transfer with slip flow from a spinning disk with viscous dissipation and Ohmic heating yields a system of non-linear, coupled, ordinary differential equations. These equations are analytically solved by applying a newly developed method namely the DTM-Padé technique which is a combination of the Differential Transform Method (DTM) and the Padé approximation. A full analytical solution is presented, as a benchmark for alternative numerical solutions. DTM-Padé is implemented without requiring linearization, discretization, or perturbation, and holds significant potential for solving strongly nonlinear differential equations which arise frequently in fluid dynamics. The regime studied is shown to be controlled by the slip parameter (γ), magnetohydrodynamic body force parameter (M), Eckert (viscous heating) number (Ec), Schmidt number (Sc), Soret number (Sr), Dufour number (Du) and Prandtl number (Pr). The influence of selected parameters on the evolution of dimensionless velocity, temperature and concentration distributions is studied graphically. Increasing magnetic field (M) is found to significantly inhibit the radial (f) and tangential (g) velocities, but to accentuate the axial velocity field (h);furthermore temperature (θ) and concentration (φ) are both enhanced with increasing M. Increasing Soret number (Sr) acts to boost the dimensionless concentration (φ). Temperatures are significantly elevated in the boundary layer regime with a rise in Eckert number (Ec). Excellent correlation between the DTM-Padé technique and numerical (shooting) solutions is achieved. The model has important applications in industrial energy systems, process mechanical engineering, electromagnetic materials processing and electro-conductive chemical transport processes.展开更多
In this paper a definitely new analytical technique, predictor homotopy analysis method （PHAM）, is employed to solve the problem of two-dimensional nanofluid flow through expanding or contracting gaps with permeable...In this paper a definitely new analytical technique, predictor homotopy analysis method （PHAM）, is employed to solve the problem of two-dimensional nanofluid flow through expanding or contracting gaps with permeable walls. Moreover, comparison of the PHAM results with numerical results obtained by the shooting method coupled with a Runge- Kutta integration method as well as previously published study results demonstrates high accuracy for this technique. The fluid in the channel is water containing different nanoparticles： silver, copper, copper oxide, titanium oxide, and aluminum oxide. The effects of the nanoparticle volume fraction, Reynolds number, wall expansion ratio, and different types of nanoparticles on the flow are discussed.展开更多
Thermal energy storage technology has the advantages of high energy storage density,small size,and high energy conversion efficiency.It is one of the key energy storage technologies and an important way to achieve car...Thermal energy storage technology has the advantages of high energy storage density,small size,and high energy conversion efficiency.It is one of the key energy storage technologies and an important way to achieve carbon peaking and carbon neutrality goals.Phase change materials (PCMs) offer this opportunity to store high amount of energy and release it in the form of latent heat when needed,and therefore have the advantage of being capable to alleviate the intrinsic intermittency of renewable power production,especially in wind and solar farms.展开更多
The paper provides an analytical investigation, homotopy analysis method （HAM）, of the heat and mass transfer for magnetohydrodynamic Oldroyd-B nanofluid flow over a stretching sheet in the presence of convective bo...The paper provides an analytical investigation, homotopy analysis method （HAM）, of the heat and mass transfer for magnetohydrodynamic Oldroyd-B nanofluid flow over a stretching sheet in the presence of convective boundary condition. The PDE governing equations, which consist of equations of continuity, momentum, energy and nanoparti- cles, are converted to ordinary differential equations using similarity transformations. The current HAM solution demonstrates very good correlation with those of the pre- viously published studies in the special cases. The influences of different flow physical parameters such as the Deborah numbers in terms of relaxation and retardation times （/3i, /32）, magnetic parameter （M）, Prandtl number （Pr）, Brownian motion parameter （Nb）, thermophoresis parameter （Nt）, Lewis number （Le）, and Biot number （Bi） on he fluid velocity component （f＇（η））, temperature distribution （θ（η）） and concentration φ（η）） as well as the local Nusselt number （Nux/Rex ） and the local Sherwood number （Shx/Re1/2 ） are discussed in detail.展开更多
文摘A similarity solution for the steady hydromagnetic convective heat and mass transfer with slip flow from a spinning disk with viscous dissipation and Ohmic heating yields a system of non-linear, coupled, ordinary differential equations. These equations are analytically solved by applying a newly developed method namely the DTM-Padé technique which is a combination of the Differential Transform Method (DTM) and the Padé approximation. A full analytical solution is presented, as a benchmark for alternative numerical solutions. DTM-Padé is implemented without requiring linearization, discretization, or perturbation, and holds significant potential for solving strongly nonlinear differential equations which arise frequently in fluid dynamics. The regime studied is shown to be controlled by the slip parameter (γ), magnetohydrodynamic body force parameter (M), Eckert (viscous heating) number (Ec), Schmidt number (Sc), Soret number (Sr), Dufour number (Du) and Prandtl number (Pr). The influence of selected parameters on the evolution of dimensionless velocity, temperature and concentration distributions is studied graphically. Increasing magnetic field (M) is found to significantly inhibit the radial (f) and tangential (g) velocities, but to accentuate the axial velocity field (h);furthermore temperature (θ) and concentration (φ) are both enhanced with increasing M. Increasing Soret number (Sr) acts to boost the dimensionless concentration (φ). Temperatures are significantly elevated in the boundary layer regime with a rise in Eckert number (Ec). Excellent correlation between the DTM-Padé technique and numerical (shooting) solutions is achieved. The model has important applications in industrial energy systems, process mechanical engineering, electromagnetic materials processing and electro-conductive chemical transport processes.
文摘In this paper a definitely new analytical technique, predictor homotopy analysis method （PHAM）, is employed to solve the problem of two-dimensional nanofluid flow through expanding or contracting gaps with permeable walls. Moreover, comparison of the PHAM results with numerical results obtained by the shooting method coupled with a Runge- Kutta integration method as well as previously published study results demonstrates high accuracy for this technique. The fluid in the channel is water containing different nanoparticles： silver, copper, copper oxide, titanium oxide, and aluminum oxide. The effects of the nanoparticle volume fraction, Reynolds number, wall expansion ratio, and different types of nanoparticles on the flow are discussed.
文摘Thermal energy storage technology has the advantages of high energy storage density,small size,and high energy conversion efficiency.It is one of the key energy storage technologies and an important way to achieve carbon peaking and carbon neutrality goals.Phase change materials (PCMs) offer this opportunity to store high amount of energy and release it in the form of latent heat when needed,and therefore have the advantage of being capable to alleviate the intrinsic intermittency of renewable power production,especially in wind and solar farms.
文摘The paper provides an analytical investigation, homotopy analysis method （HAM）, of the heat and mass transfer for magnetohydrodynamic Oldroyd-B nanofluid flow over a stretching sheet in the presence of convective boundary condition. The PDE governing equations, which consist of equations of continuity, momentum, energy and nanoparti- cles, are converted to ordinary differential equations using similarity transformations. The current HAM solution demonstrates very good correlation with those of the pre- viously published studies in the special cases. The influences of different flow physical parameters such as the Deborah numbers in terms of relaxation and retardation times （/3i, /32）, magnetic parameter （M）, Prandtl number （Pr）, Brownian motion parameter （Nb）, thermophoresis parameter （Nt）, Lewis number （Le）, and Biot number （Bi） on he fluid velocity component （f＇（η））, temperature distribution （θ（η）） and concentration φ（η）） as well as the local Nusselt number （Nux/Rex ） and the local Sherwood number （Shx/Re1/2 ） are discussed in detail.
