We investigated the time‐dependent viscoelastic fluid flow through a parallel‐plate microchannel under the influence of a transversely applied magnetic field and an axially imposed electric field. We performed the analysis by employing the Poisson‐Boltzmann equation under the Debye‐Huckel approximation. The generalized second‐grade fluid model with a fractional‐order time derivative is used to observe the non‐Newtonian and fractional behavior rates of deformation employing the Riemann‐Liouville fractional operator. We considered the asymmetric zeta potentials and different slip effects at the walls to study the flow behavior near the vicinity of the channel. We obtained an analytical solution in terms of Mittag‐Leffler function, applying Fourier and Laplace transformations. We imposed the heat transfer phenomena with the dissipation of energy and Joule heating effects on the model. The governing equations were also solved numerically by employing an implicit finite difference scheme. The numerical solution was compared with the analytical results, considering the influence of the pertinent parameters involved in the problem. The study delineates that the flow rate decreases with a rise in the fractional‐order parameter, while the opposite trend is observed with the electroosmotic parameter. Due to the application of sufficient strength of the magnetic field and the Joule heating effects, the temperature increases within the channel.
Laser cutting of mild steel has been widely used in the manufacturing industries for many decades because of its accuracy and efficiency. The present work deals with design of a supersonic nozzle for laser cutting of thick carbon steel by a sub 1 kW laser system utilizing the heat generated from the oxidation process. In this case, most of the power required for cutting operation is contributed by the exothermic reaction and laser is used only for heating the material to facilitate oxidation. The critical part in the proposed approach is the design of a suitable supersonic nozzle, which is discussed in thispaper. An axi-symmetric, straight small supersonic nozzle has been designed.The nozzle profile is designed on the basis of Method of Characteristics (MOC) and its performance has been evaluated and compared with results obtained from FLUENT. The distribution of pressure, velocity and gas density are predicted and mapped. The behavior of the supersonic jet from the nozzle exit has been investigated using Computational Fluid Dynamics (CFD) and validated experimentally using shadowgraph techniques. The designed supersonic nozzle exhibits good gas dynamic characteristics under high operating pressure. Cutting trials have been conducted using the nozzle assembly with satisfactory performance. A Area [m 2 ] x, r, ζ Cartesian co-ordinates [m/s] Cle> Qf» C3ε, ^μ Constants Greek symbols * D Diameter [m] Ρ Density [Kg/m 3 ] G k Generation of turbulent kinetic energy due σ Μ & σ ε Turbulent Prandtl numbers for k and G k to the mean velocity gradients [kg/ms 3 ] σ Μ & σ ε ε respectively Generation of turbulent kinetic energy due Dissipation rate of turbulent kinetic to buoyancy [kg/ms 3 ] ε energy [m 2 /s 3 ] k Turbulent kinetic energy [m 2 /s 2 ] θ Streamline angle [rad] L t Length of initial expansion region [m/s] ν Prandtl-Meyer angle [rad] Μ Mach number Mmol Molecular viscosity [kg/ms] Μ, Turbulent Mach number Veff Effective viscosity [kg/ms] Ρ Pressure [bar] Μι Turbulent viscosity [kg/ms] R Gas constant [ J/kg mol-K] Μ Dynamic viscosity [kg/ms] s k User-defined source terms [kg/ms 3 ] Ύ Specific heat ratio
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.