Obaid Ullah Mehmood

A Note on Radiative Heat Transfer to Peristaltic Flow of Sisko Fluid.

This paper looks at the effects of radiative heat transfer on the peristaltic transport of a Sisko fluid in an asymmetric channel with nonuniform wall temperatures. Adopting the lubrication theory, highly nonlinear coupled governing equations involving power law index as an exponent have been linearized and perturbation solutions are obtained about the Sisko fluid parameter. Analytical solutions for the stream function, axial pressure gradient, axial velocity, skin friction, and Nusselt number are derived for three different cases (i.e., shear thinning fluid, viscous fluid, and shear thickening fluid). The effects of Grashof number, radiation parameter, and other configuration parameters on pumping, trapping, temperature, Nusselt number, and skin friction have been examined in detail. A good agreement has been found for the case of viscous fluid with existing results.

Hydromagnetic nanofluid flow past a stretching cylinder embedded in non-Darcian Forchheimer porous media

AbstractThe present article presents the hydromagnetic nanofluid flow past a stretching cylinder embedded in non-Darcian Forchheimer porous media by using Buongiorno’s mathematical model (Buongiorno in J Heat Transf 128:240–250, 2006; Nadeem et al. in J Taiwan Inst Chem Eng 45:121, 2014, Nadeem et al. Appl Nanosci 4:625–631, 2014). Thermal radiation via Roseland’s approximation (Akbar et al. in Chin J Aeronaut 26:1389–1397, 2013; Nadeem and Haq in J Aerosp Eng 28:04014061, 2012), Brownian motion, thermophoresis and Joule heating effects are also considered. To explore thermal characteristics, prescribed heat flux and prescribed mass flux boundary conditions are deployed. Governing flow problem consists of PDEs in the cylindrical form, which are converted into system of nonlinear ODEs by applying applicable similarity transforms. ODEs are tackled by RK–Fehlberg fourth–fifth-order numerical integration scheme with shooting algorithm. Impact of numerous involving physical parameters on flow features like temperature distribution, velocity distribution, Sherwood number, local Nusselt number and skin friction coefficient is shown through graphs and tables.

Simultaneous effects of dissipative heating and partial slip on peristaltic transport of Sisko fluid in asymmetric channel

This paper looks at the dissipative heat transfer on the peristaltic flow of a Sisko fluid in an asymmetric channel. Flow exhibits slip at the channel walls maintained at nonuniform temperatures. Long wavelength approximation is utilized and perturbation solutions are obtained about Sisko fluid parameter. Closed form solutions for the stream function, axial pressure gradient, axial velocity, temperature and the heat transfer coefficient are presented. Influences of various interesting parameters are presented in graphical and tabular forms. Pumping and trapping phenomena are discussed for increasing velocity slip parameter. A comparative study on temperature and heat transfer coefficient for viscous, shear thinning and shear thickening fluids has been presented. Comparisons for viscous fluid are found in good agreement.

Electromagnetohydrodynamic transport of Al2O3 nanoparticles in ethylene glycol over a convectively heated stretching cylinder

In this study, the transport of Al2O3 nanoparticles in ethylene glycol conventional fluid over a linearly stretching cylinder is investigated. The current research employs a convective surface boundary condition for heat transfer exploration. Flux model proposed by Rosseland is employed to examine effect of thermal radiations. The governing flow problem comprises highly nonlinear ordinary differential equations. Similarity transformations are used to reduce the equations in similar forms, which are then solved by Runge–Kutta–Fehlberg fourth-fifth order numerical scheme with shooting algorithm in MATLAB software. In order to authenticate the accuracy of our results, we have contrasted results with those obtained by Ishak et al., Wang, and Pandey and Kumar and found that they are in better concord, as revealed in Table 2. The impact of numerous emerging parameters on velocity distribution and heat transfer distribution are argued in all aspects and depicted through graphs.

Non-linear peristaltic flow of Walter's B fluid in an asymmetric channel with heat transfer and chemical reactions

In this paper, effects of heat and mass transfer on peristaltic transport of Walters B fluid in an asymmetric channel are investigated. The governing equations are solved using regular perturbation method by taking wave number as a small parameter. Expressions for the stream function, temperature distribution, heat transfer coefficient, and mass concentration are presented in explicit form. Solutions are analyzed graphically for different values of arising parameters such as viscoelastic parameter, Prandtl, Eckert, Soret, Schmidt, and Reynolds number. It has been found that these parameters considerably affect the considered flow characteristics. Results show that with an increase in Eckert and Prandtl number temperature and heat transfer coefficient increase while mass concentration decreases. Further, Mass concentration also decreases with increasing Soret and Schmidt number.

Thermal diffusion and diffusion thermo effects on peristaltic flow of sisko fluid in nonuniform channel with dissipative heating

This investigation deals with thermal diffusion and diffusion thermo effects on the peristaltic flow of a Sisko fluid in an asymmetric channel. The mode of dissipative heat transfer is taken into account with nonuniform wall temperatures. Long wavelength approximation is utilized. Solutions for the highly nonlinear coupled governing equations involving power law index as an exponent are derived by employing the perturbation technique in a Sisko fluid parameter. Closed form solutions for the stream function, the axial pressure gradient, the skin friction, the temperature, the concentration, and the Nusselt number are presented. Effects of various interesting parameters are graphically interpreted. A comparative study between Newtonian, shear thinning, and shear thickening fluids is also presented. Comparison with published results for the case of viscous fluid is observed in good agreement.

Hydromagnetic solid–liquid pulsatile flow through concentric cylinders in a porous medium

The current research is reported about the hydromagnetic solid–liquid flow in an annulus between two concentric circular cylinders embedded in a porous media. The impact of joule heating is also accounted for. Unlike the usually applied constant pressure gradient, the pulsatile pressure gradient is employed. The flow problem is first modeled and then tackled by Runge–Kutta–Fehlberg fourth–fifth-order (RKF45) numerical scheme along with shooting algorithm. The impacts of emerging parameters namely magnetic field parameter and porosity parameter on velocity and temperature distributions are displayed through graphs and briefly addressed.Graphical abstract