Entropy generation analysis of radiative Williamson fluid flow in an inclined microchannel with multiple slip and convective heating boundary effects

The main theme of the current work is to investigate the flow and heat transport characteristics of non-Newtonian Williamson fluid in an inclined micro-channel along with entropy generation analysis. The significance of the thermal radiation, convective boundary condition, and multiple slip effects is explored. The entropy generation of the system has been analyzed by adopting the 2nd law of thermodynamics. The rheological expressions of the Williamson fluid model are also taken into account. The nonlinear system is tackled by using the finite element method. An appropriate comparison has been made with previously published results in the literature as a limiting case of the considered problem. The comparison confirmed an excellent agreement. Detailed discussion of the significance of effective parameters on Bejan number, entropy generation rate, temperature and velocity is presented through graphs. The numerical results portray that the entropy generation and Bejan number have escalating behavior to the higher value of angle of inclination. Furthermore, the Bejan number changing its behavior at two points for different values of Reynolds’ number.

Dynamics of Multiple Slip and Thermal Radiation on Hydromagnetic Casson Nanofluid Flow over a Nonlinear Porous Stretchable Surface

Aims/ Objectives: This paper examines the dynamics of multiple slip together with thermal radiation effects on the transport of a magnetohydrodynamic Casson nanofluid passing a nonlinear porous stretchable sheet in the existence of viscous dissipation and chemical reaction.Study Design: Cross-sectional study. Methodology: The outlining equations modeling the transport phenomenon are simplified into nonlinear ordinary differential equations via the approach of similarity transformations and subsequently analyzed numerically by shooting techniques alongside Runge-Kutta Fehlberg scheme.Results: The outcomes of decisive parameters affecting the flow, heat, and nanoparticle concentration are graphically deliberated. From the investigation, it is revealed that Brownian motion, viscous dissipation, and thermophoresis parameters augment the thermal boundary layer and propel an upward growth in the temperature profile. Furthermore, the slip factor decelerates the flow and heat dissipation while the fluid movement drags in the existence of the magnetic field. Conclusion: The results obtained in this study compared favourably well with existing related studies in literature under limiting scenarios.

Strain hardening recovery mediated by coherent precipitates in lightweight steel

We investigated the effect of κ-carbide precipitates on the strain hardening behavior of aged Fe–Mn-Al-C alloys by microstructure analysis. The κ-carbides-strengthened Fe–Mn-Al-C alloys exhibited a superior strength-ductility balance enabled by the recovery of the strain hardening rate. To understand the relation between the κ-carbides and strain hardening recovery, dislocation gliding in the aged alloys during plastic deformation was analyzed through in situ tensile transmission electron microscopy (TEM). The in situ TEM results confirmed the particle shearing mechanism leads to planar dislocation gliding. During deformation of the 100 h-aged alloy, some gliding dislocations were strongly pinned by the large κ-carbide blocks and were prone to cross-slip, leading to the activation of multiple slip systems. The abrupt decline in the dislocation mean free path was attributed to the activation of multiple slip systems, resulting in the rapid saturation of the strain hardening recovery. It is concluded that the planar dislocation glide and sequential activation of slip systems are key to induce strain hardening recovery in polycrystalline metals. Thus, if a microstructure is designed such that dislocations glide in a planar manner, the strain hardening recovery could be utilized to obtain enhanced mechanical properties of the material.