A perturbation analysis is presented in this paper for the electroosmotic (EO) flow of an Eyring fluid through a wide rectangular microchannel that rotates about an axis perpendicular to its own. Mildly shear-thinning...A perturbation analysis is presented in this paper for the electroosmotic (EO) flow of an Eyring fluid through a wide rectangular microchannel that rotates about an axis perpendicular to its own. Mildly shear-thinning rheology is assumed such that at the leading order the problem reduces to that of Newtonian EO flow in a rotating channel, while the shear thinning effect shows up in a higher-order problem. Using the relaxation time as the small ordering parameter, analytical solutions are deduced for the leading- as well as first-order problems in terms of the dimensionless Debye and rotation parameters. The velocity profiles of the Ekman-electric double layer (EDL) layer, which is the boundary layer that arises when the Ekman layer and the EDL are comparably thin, are also deduced for an Eyring fluid. It is shown that the present perturbation model can yield results that are close to the exact solutions even when the ordering parameter is as large as order unity. By this order of the relaxation time parameter, the enhancing effect on the rotating EO flow due to shear-thinning Eyring rheology can be significant.展开更多
In consideration of the electroosmotic flow in a slit microchannel, the con-stitutive relationship of the Eyring fluid model is utilized. Navier's slip condition is used as the boundary condition. The governing equat...In consideration of the electroosmotic flow in a slit microchannel, the con-stitutive relationship of the Eyring fluid model is utilized. Navier's slip condition is used as the boundary condition. The governing equations are solved analytically, yielding the velocity distribution. The approximate expressions of the velocity distribution are also given and discussed. Furthermore, the effects of the dimensionless parameters, the electrokinetic parameter, and the slip length on the flow are studied numerically, and appropriate conclusions are drawn.展开更多
This article investigates the three-dimensional flow of Powell–Eyring nanofluid with thermophoresis and Brownian motion effects. The energy equation is considered in the presence of thermal radiation. The heat and ma...This article investigates the three-dimensional flow of Powell–Eyring nanofluid with thermophoresis and Brownian motion effects. The energy equation is considered in the presence of thermal radiation. The heat and mass flux conditions are taken into account. Mathematical formulation is carried out through the boundary layer approach. The governing partial differential equations are transformed into the nonlinear ordinary differential equations through suitable variables. The resulting nonlinear ordinary differential equations have been solved for the series solutions. Effects of emerging physical parameters on the temperature and nanoparticles concentration are plotted and discussed. Numerical values of local Nusselt and Sherwood numbers are computed and examined.展开更多
In this article,heat and mass transfer with Joule heating on magnetohydrodynamic(MHD)peristaltic blood under the influence of Hall effect is examined.Mathematical modelling is based on momentum,energy and concentratio...In this article,heat and mass transfer with Joule heating on magnetohydrodynamic(MHD)peristaltic blood under the influence of Hall effect is examined.Mathematical modelling is based on momentum,energy and concentration which are taken into account using ohms law.The governing partial differential equations are further simplified by neglecting the inertial forces and long wavelength approximations.Exact solutions have been presented for velocity,temperature and concentration profile.The influence of all the physical pertinent parameters is taken into account with the help graphs.It is found that Hartmann number and Hall parameter shows opposite behaviour on velocity,temperature and concentration profile.It is worth mentioning that pressure rise also depicts opposite behaviour for Hartmann number and Hall parameter.The present analysis is also presented for Newtonian fluid(α→0)as a special case for our study.It is observed that Hall Effect and magnetic field shows opposite behaviour on velocity and temperature profile.Temperature profile increases due to the increment in Prandtl number and Eckert number.Numerical comparison is also presented between the existing published results by takingα=0;M=0 as a special case of our study.展开更多
基金financially supported by the Research Grants Council of the Hong Kong Special Administrative Region, China, through General Research Fund Project HKU 715510E and 17206615the University of Hong Kong through the Small Project Funding Scheme under Project Code 201309176109
文摘A perturbation analysis is presented in this paper for the electroosmotic (EO) flow of an Eyring fluid through a wide rectangular microchannel that rotates about an axis perpendicular to its own. Mildly shear-thinning rheology is assumed such that at the leading order the problem reduces to that of Newtonian EO flow in a rotating channel, while the shear thinning effect shows up in a higher-order problem. Using the relaxation time as the small ordering parameter, analytical solutions are deduced for the leading- as well as first-order problems in terms of the dimensionless Debye and rotation parameters. The velocity profiles of the Ekman-electric double layer (EDL) layer, which is the boundary layer that arises when the Ekman layer and the EDL are comparably thin, are also deduced for an Eyring fluid. It is shown that the present perturbation model can yield results that are close to the exact solutions even when the ordering parameter is as large as order unity. By this order of the relaxation time parameter, the enhancing effect on the rotating EO flow due to shear-thinning Eyring rheology can be significant.
基金Project supported by the National Natural Science Foundation of China(Nos.11102102 and 91130017)the Independent Innovation Foundation of Shandong University(No.2013ZRYQ002)
文摘In consideration of the electroosmotic flow in a slit microchannel, the con-stitutive relationship of the Eyring fluid model is utilized. Navier's slip condition is used as the boundary condition. The governing equations are solved analytically, yielding the velocity distribution. The approximate expressions of the velocity distribution are also given and discussed. Furthermore, the effects of the dimensionless parameters, the electrokinetic parameter, and the slip length on the flow are studied numerically, and appropriate conclusions are drawn.
文摘This article investigates the three-dimensional flow of Powell–Eyring nanofluid with thermophoresis and Brownian motion effects. The energy equation is considered in the presence of thermal radiation. The heat and mass flux conditions are taken into account. Mathematical formulation is carried out through the boundary layer approach. The governing partial differential equations are transformed into the nonlinear ordinary differential equations through suitable variables. The resulting nonlinear ordinary differential equations have been solved for the series solutions. Effects of emerging physical parameters on the temperature and nanoparticles concentration are plotted and discussed. Numerical values of local Nusselt and Sherwood numbers are computed and examined.
文摘In this article,heat and mass transfer with Joule heating on magnetohydrodynamic(MHD)peristaltic blood under the influence of Hall effect is examined.Mathematical modelling is based on momentum,energy and concentration which are taken into account using ohms law.The governing partial differential equations are further simplified by neglecting the inertial forces and long wavelength approximations.Exact solutions have been presented for velocity,temperature and concentration profile.The influence of all the physical pertinent parameters is taken into account with the help graphs.It is found that Hartmann number and Hall parameter shows opposite behaviour on velocity,temperature and concentration profile.It is worth mentioning that pressure rise also depicts opposite behaviour for Hartmann number and Hall parameter.The present analysis is also presented for Newtonian fluid(α→0)as a special case for our study.It is observed that Hall Effect and magnetic field shows opposite behaviour on velocity and temperature profile.Temperature profile increases due to the increment in Prandtl number and Eckert number.Numerical comparison is also presented between the existing published results by takingα=0;M=0 as a special case of our study.