Double diffusive convection and Hall effect in creeping flow of viscous nanofluid through a convergent microchannel: a biotechnological applications.

Current analysis presents the mathematical modeling for peristaltic transport of nanofluid with applications of double-diffusive convection and Hall features. The flow has been induced by a convergent channel due to peristaltic propulsion. These rheological equations are transformed from fixed to wave frames by using a linear mathematical relation between these two frames. The dimensionless variables are used to transform these rheological equations into nondimensional forms. The flow analysis is carried out under two distinct scientific biological assumptions, one is known as long wavelength and the second one is low Reynolds number. The analytical solutions of these rheological equations are obtained with the help of a rigorous analytical method known as integration in the term of stream function. The physical effects of magnetic and Hall devices, respectively, on the flow features are also considered in the present analysis. The physical influences of dominant hydro-mechanical parameters on the axial velocity, pressure gradient, trapping, volumetric fraction of nanofluid, heat and mass transfer phenomena are studied. The complex scenario of biomimetic propulsions are considered in boundary walls to boost the proficiency of peristaltic micropumps.

Transportation of entropy optimization in radiated chemically dissipative flow of Prandtl-Eyring nanofluid with activation energy.

BACKGROUND: There are frequent strategies to enhance the efficiency of heat transport. Some strategies are employed of extended surfaces, utilization of vibration to the heat transport surfaces, and use of small scale channels. Efficiency of heat transport can also be enhanced by intensifying the thermal conductivity of working material. Engine oil, water and ethylene glycol are frequently utilized for heat transport liquids having comparatively low thermal conductivities then solids. Thermal conductivity of solids can be employed to improve the thermal conductivity of fluid through addition of nano or micro type solid particles to that liquid. The viability of usage of such materials with sizes 2 µm or millimeters was recently scrutinized by numerous engineers and analyst. In this communication, we aim to analyze flow of non-Newtonian nanomaterial (Prandtl-Eyring nanofluid). Features of nanofluid discussed with Brownian and thermophoresis diffusion. Entropy generation, thermal radiation, dissipation, activation energy, Joule heating and radiative heat flux is discussed. METHOD: Homotopic convergent solutions are developed by using OHAM. Governing nonlinear equations are developed. RESULTS AND CONCLUSION: Fluid variable has opposite behavior on temperature and velocity. For larger thermophoresis parameter, temperature and concentration are increased. Concentration is reduced by improving Brownian motion parameter while temperature increases. Entropy generation improves with larger fluid parameter and Brinkman number, while Bejan number has opposite effect.

Eyring-Powell nanofluid flow with nonlinear mixed convection: Entropy generation minimization.

BACKGROUND: Entropy is the amount of energy which is lost during any irreversible process. Here our main focus is that how can we reduce this energy loss to enhance the capability of our system. Blood is an example of Eyring-Powell fluid. Many strategies are used to rise the capacity of heat transport. Heat transport can be enhanced by intensifying the materials thermal conductivity through nanoparticles. Thermal conductivity of the material can be enhanced by adding nanoparticles in base fluid. The objective of this work is to discuss entropy generation in MHD Eyring-Powell nanofluid flow. The flow is generated by a linear stretchable surface. Current analysis includes the effects of viscous dissipation, nonlinear mixed convection and Joule heating. Nanoparticles analyzed the consequences of Brownian motion and thermophoresis effects. METHOD: The boundary layer flow equations are solved for series solutions by applying homotopic technique. RESULTS AND CONCLUSION: Graphical results of involved quantities like entropy generation, velocity, concentration and thermal fields are presented. Skin friction, Sherwood and Nusselt number are numerically scrutinized.

MHD Flow and Heat Transfer between Coaxial Rotating Stretchable Disks in a Thermally Stratified Medium.

This paper investigates the unsteady MHD flow of viscous fluid between two parallel rotating disks. Fluid fills the porous space. Energy equation has been constructed by taking Joule heating, thermal stratification and radiation effects into consideration. We convert system of partial differential equations into system of highly nonlinear ordinary differential equations after employing the suitable transformations. Convergent series solutions are obtained. Behavior of different involved parameters on velocity and temperature profiles is examined graphically. Numerical values of skin friction coefficient and Nusselt number are computed and inspected. It is found that tangential velocity profile is increasing function of rotational parameter. Fluid temperature reduces for increasing values of thermal stratification parameter. At upper disk heat transfer rate enhances for larger values of Eckert and Prandtl numbers.

Impact of Cattaneo-Christov Heat Flux in Jeffrey Fluid Flow with Homogeneous-Heterogeneous Reactions.

Two-dimensional stretched flow of Jeffrey fluid in view of Cattaneo-Christov heat flux is addressed. Effects of homogeneous-heterogeneous reactions are also considered. Suitable transformations are used to form ordinary differential equations. Convergent series solutions are computed. Impact of significant parameters on the velocity, temperature, concentration and skin friction coefficient is addressed. Analysis of thermal relaxation is made. The obtained results show that ratio of relaxation to retardation times and Deborah number have inverse relation for velocity profile. Temperature distribution has decreasing behavior for Prandtl number and thermal relaxation time. Also concentration decreases for larger values of strength of homogeneous reaction parameter while it increases for strength of heterogeneous reaction parameter.