Non-Coaxially Rotating Motion in Casson Martial along with Temperature and Concentration Gradients via First-Order Chemical Reaction

The effect of non-coaxial rotation on the transport of mass subjected to first-order chemical reaction is studied analytically. The effects of thermal radiation, buoyancy, constructive and destructive chemical reactions along with Casson fluid in rotating frame are discussed. Time evolution of primary and secondary velocities, energy and solute particles are analyzed. The behavior of flow under the variation of intensity of magnetic field is also investigated. Evolutionary behavior of primary velocity is opposite to the evolutionary behavior of secondary velocity. The impact of buoyant force on primary velocity is opposite to the role of buoyant force on the secondary velocity. The evolutionary behavior of temperature is also examined and a remarkable enhancement in temperature is noticed. Thermal radiation causes the fluid to be cooled down as heat energy is escaped by thermal radiation. Evolutionary behavior of concentration is also analyzed and an increasing of concentration versus time is noted. Destructive chemical reaction results a remarkable reduction in the concentration and vice versa for generative chemical reaction.

Flow velocity behavior programming on open channel bends

Flow velocity on open channel bends generally experiences additional velocity which is called secondary velocity. This paper aims to analyse and calculate the velocity that occurs in an open channel bend in general. The calculation that the writer uses is the calculation with fortran programming, in a case study of a river that bends, where the variables that must be present are given. The results of calculations and measurements of Secondary Speeds that occur at channel bends in this Open Channel will be very useful for river channel improvement or flood prevention in river channels, especially on existing bends. The conclusion is that at the bend of an open channel or river, there will be an increase in flow velocity in the transverse direction. This additional velocity is caused by the additional secondary velocity, namely the transverse velocity.

Magnetic Rotating Flow of a Hybrid Nano-Materials Ag-MoS2 and Go-MoS2 in C2H6O2-H2O Hybrid Base Fluid over an Extending Surface Involving Activation Energy: FE Simulation

Numeric simulations are performed for a comparative study of magnetohydrodynamic (MHD) rotational flow of hybrid nanofluids (MoS2-Ag/ethyleneglycol-water (50–50%) and MoS2-Go/ethyleneglycol-water (50–50%)) over a horizontally elongated plane sheet. The principal objective is concerned with the enhancement of thermal transportation. The three-dimensional formulation governing the conservation of mass, momentum, energy, and concentration is transmuted into two-dimensional partial differentiation by employing similarity transforms. The resulting set of equations (PDEs) is then solved by variational finite element procedure coded in Matlab script. An intensive computational run is carried out for suitable ranges of the particular quantities of influence. The primary velocity component decreases monotonically and the magnitude of secondary velocity component diminishes significantly when magnetic parameter, rotational parameter, and unsteadiness parameter are incremented. Both the primary and secondary velocities are smaller in values for the hybrid phase Ag-MoS2 than that of hybrid phase Go-MoS2 but the nanoparticle concentration and temperature are higher for hybrid phase Ag-MoS2. The increased values of parameters for thermophoresis, Brownian motion, shape factor, and volume fraction of ϕ2 made significant improvement in the temperature of the two phases of nano liquids. Results are also computed for the coefficients of skin friction(x, y-directions), Nusselt number, and Sherwood number. The present findings manifest reasonable comparison to their existing counterparts. Some of the practical engineering applications of the present analysis may be found in high-temperature nanomaterial processing technology, crystal growing, extrusion processes, manufacturing and rolling of polymer sheets, academic research, lubrication processes, and polymer industry.

Adomain computation of radiative-convective bi-directional stretching flow of a magnetic non-Newtonian fluid in porous media with homogeneous–heterogeneous reactions

In the present communication, the laminar, incompressible, hydromagnetic flow of an electrically conducting non-Newtonian (Sisko) fluid over a bi-directional stretching sheet in a porous medium is studied theoretically. Thermal radiation flux, homogeneous–heterogeneous chemical reactions and convective wall heating are included in the model. The resultant nonlinear ordinary differential equations with transformed boundary conditions via similarity transformation are then solved with the semi-analytical Adomain Decomposition Method (ADM). Validation with earlier studies is included for the nonradiative case. Extensive visualization of velocity, temperature and species concentration distributions for various emerging parameters is included. Increasing the magnetic field and inverse permeability parameter is observed to decelerate both the primary and secondary velocity magnitudes whereas they increase temperatures in the regime. Increasing sheet stretching ratio weakly accelerates the primary flow throughout the boundary layer whereas it more dramatically accelerates the secondary flow near sheet surface. Temperature is consistently reduced with increasing stretching sheet ratio whereas it is strongly enhanced with greater radiative parameter. With greater Sisko non-Newtonian power-law index the primary velocity and temperature are decreased whereas the secondary velocity is increased. Increasing both homogenous and heterogeneous chemical reaction parameters is found to weakly and more strongly, respectively, deplete concentration magnitudes whereas greater Schmidt number enhances them.

Finite Element Numerical Investigation into Unsteady MHD Radiating and Reacting Mixed Convection Past an Impulsively Started Oscillating Plate

In this article, numerical investigation is carried out for the unsteady MHD mixed convection flow of radiating and chemically reacting fluid past an impulsively started oscillating vertical plate with variable temperature and constant mass diffusion. The transport model employed includes the Hall current. A uniform magnetic field is applied transversely to the direction of the fluid flow. The flow consideration is subject to small magnetic Reynolds number. The Rosseland approximation is used to describe the radiation heat flux in the energy equation. The dimensionless governing system of partial differential equations of the flow has been solved numerically by employing the FEM. The influence of pertinent parameters on primary velocity, secondary velocity, temperature and concentration are presented graphically whereas primary skin friction, secondary skin friction, Nusselt number and Sherwood number are presented in tabular form. The findings of the present study are in good agreement with the earlier reported studies.

Micro-Slit Cutting in an Aluminum Foil Using an Un-Traveling Tungsten Wire

Microslit cutting in aluminum foils is considered to be difficult as aluminum foils have low hardness and deformability. In this study, a novel cutting method is proposed where a tungsten microwire is utilized as the tool to cut aluminum foil without tool traveling or spinning. A statics simulation is first performed to analyze the cutting mechanism. Further, a tungsten wire with a diameter of 50 μm is utilized as the tool and a series of experiments are carried to discuss how the feeding rate influences slit width and roughness. With optimal parameters, it takes only 100 s to fabricate a 5 mm long microslit with an average width of 48.75 μm, width standard deviation of 1.48 μm, and surface roughness of 0.110 μm when applying initial/secondary velocity of 50/50 μm·s−1.

Fully developed magnetohydrodynamics natural convection flow in a vertical micro-porous-channel with Hall effects

An exact solution is presented for the steady hydromagnetic fully developed natural convection flow in a vertical microporous channel due to asymmetric heating. The governing momentum and energy equations are presented in dimensionless form and solved analytically using the method of undetermined coefficient. The effects of Hall current and suction/injection parameters on the primary and secondary velocity, volume flow rates, and skin frictions are discussed with the help of line graphs and tables. It is observed that injection accelerates the flow, whereas suction retards the flow in both the primary and secondary flow directions.

Post-transitional periodic flow in a straight square duct

Direct numerical simulation of incompressible turbulence in a straight square duct finds the post-transition flow evolving substantially, and for Reynolds numbers based on the friction velocity and duct hydraulic radius greater than 600 a two-structure secondary flow regime has been established, suggesting the coexistence of two distinct sources of mean streamwise vorticity. The nominal source terms in the equation for the mean streamwise vorticity involve turbulent variables only, that allow us to identify the dominant dynamical process that marks and/or sustains the transverse mean flow. Close to the corner a mean profile instability is dominant, while farther away turbulent streamwise vorticity intensification is broadly distributed near the duct walls. The instability-driven secondary velocity maximum on the duct diagonals scales with the friction velocity. There is limited scaling of turbulent intensities on the wall bisectors.

Rotating Hydromagnetic Two-Fluid Convective Flow and Temperature Distribution in an Inclined Channel

Magnetohydrodynamic convective two-fluid flow and temperature distribution between two inclined parallel plates in which one fluid being electrically non-conducting and the other fluid is electrically conducting is studied. A constant magnetic field is applied normal to the flow. The system is rotated about y-axis with an angular velocity ‘W’. Perturbation method is used to obtain solutions for primary velocity, secondary velocity and temperature distribution by assuming that the fluids in the two regions are incompressible, laminar, steady and fully developed. Increasing values of rotation is to reduce temperature distribution and primary velocity where as thesecondary velocity increases for smaller rotation, while for larger rotation it decreases.

Hall Effect on MHD Transient Flow Past an Impulsively Started Infinite Horizontal Porous Plate in a Rotating System

In this paper, the effect of Hall current on an unsteady MHD transient three dimensional flow of an electrically conducting viscous incompressible fluid past an impulsively started infinite horizontal porous plate relative to a rotating system has been studied. It is assumed that the entire system rotates with a constant angular velocity about the normal to the plate and a uniform magnetic field is applied along the normal to the plate and directed into the fluid region. The magnetic Reynolds number is assumed to be so small that the induced magnetic field can be neglected. The expressions for the primary and secondary fields and shearing stress at the plate due to primary and secondary velocity fields are obtained in a non-dimensional form. The non-dimensional governing equations of the flow are solved by using the Galerkin FEM. The effects of the physical parameters, such as the Hartmann number (M), rotation parameter (Ω), porosity parameter (K) and Hall parameter (m) on primary and secondary velocities and shearing stresses τx and τy due to primary and secondary velocities are discussed through graphs and tables, and results are physically interpreted.