• Energy Research

The existing investigation highlights oblique Jeffrey fluid with mixed convection on a stretched surface. Also chemical reactions with properties of homogeneity and heterogeneity are considered. The leading physical model is converted in a non-linear system of ODE by means of proper similarity alterations. Influence of all relative physical constraints on velocity, temperature as well as on concentration are expressed geometrically. Physical magnitudes of interest like friction measurements, thermal and concentration transport rates of chemical spices at the surface are studied numerically.

Abstract The present study numerically investigates the oblique flow of a Walter-B type nano fluid over a convective surface. Effects of transversely applied magnetic field are also taken into account. The governing system is presented in the form of coupled differential equations by means of suitable similarity transformations which are then solved by using Spectral Quasilinearisation Method (QLM) and the Spectral Local Linearization Method (LLM). The results for velocities temperature as well as nano particle concentration are plotted against pertinent flow parameters. It is found that applied magnetic field M has opposite influence on normal and tangential components of local shear stress and it decays the local heat flux and mass flux rate at the stretching convective surface. Thermophoresis and Brownian diffusion effects on the local heat and mass flux rate are found to be non-similar in a quantitative sense. In order to signify the validity of current numerical scheme, a remarkable agreement is presented with the previous literature for some limiting cases.

Abstract Transport theories in porous media are quite operative to analyse heat transferral phenomenon in biological tissues, reducing bio convective flow instabilities by means of porous media and many more. Inspired by these remarkable features, the present study is conducted to analyse heat transfer phenomenon for obliquely striking nanofluid through a porous media. Copper (Cu) nanoparticles are suspended in traditional Hydrogen Oxide based fluid. Scaling group of transformations is conveniently employed to reduce governing transport equations and is tackled numerically afterwards. Influence of nanoparticles volume fraction, stretching ratio and porosity parameter on physical measures of concern such as normal and tangential skin friction and corresponding heat flux at wall is portrayed. Streamline patterns are traced out to discover the influence of porosity factor on actual flow behavior. It was observed that solid volume fraction of copper nanoparticles enhanced the skin friction coefficients and heat flux. Increasing the porosity parameter leads to greater heat flux and tangential skin friction co-efficient.

The present study inspects the non-aligned stagnation point nano fluid over a convective surface in the presence of partial slip.Two types of base fluids namely water and kerosene are selected with Cu nanoparticles. The governing physical problem is presented and transformed into a system of coupled nonlinear differential equations using suitable similarity transformations. These equations are then solved numerically using midpoint integration scheme along with Richardson extrapolation via Maple. Impact of relevant physical parameters on the dimensionless velocity and temperature profiles are portrayed through graphs. Physical quantities such as local skin frictions co-efficient and Nusselt numbers are tabularized. It is detected from numerical computations that kerosene-based nano fluids have better heat transfer capability compared with water-based nanofluids. Moreover it is found that water-based nanofluids offer less resistance in terms of skin friction than kerosene-based fluid. In order to authenticate our present study, the calculated results are compared with the prevailing literature and a considerable agreement is perceived for the limiting case.

The present study focuses on a crosswise stream of liquid-holding nano-sized particles over an elongating (stretching) surface. Tiny particles of copper are added into base liquid (water). The influence of the micro rotation phenomenon is also considered. By means of appropriate transformations non-linear coupled ordinary differential equations are attained that govern the flow problem. The Runge–Kutta–Fehlberg scheme, together with the shooting method, is engaged to acquire results numerically. Micropolar coupling parameter, microelements concentration and nanoparticles volume fraction effects are examined over the profiles of velocity, temperature and micro-rotation. Moreover, heat flux and shear stress are computed against pertinent parameters and presented through bar graphs. Outcomes revealed that material constant has increasing effects on normal components of flow velocity; however, it decreasingly influences the tangential velocity, micro-rotation components and temperature profile. Temperature profile appeared to be higher for weak concentration of microelements. It is further noticed that normal velocity profile is higher in magnitude for the case of strong concentration (n = 0) of microelements, whereas tangential velocity profile is higher near the surface for the case of weak concentration (n = 0.5) of microelements. An increase of 3.74% in heat flux is observed when the volume fraction of nanoparticles is increased from 1 to 5%.