A numerical study on MHD double diffusive nonlinear mixed convective nanofluid flow around a vertical wedge with diffusion of liquid hydrogen

The present study focuses on double diffusive nonlinear (quadratic) mixed convective flow of nanoliquid about vertical wedge with nonlinear temperature-density-concentration variations. This study is found to be innovative and comprises the impacts of quadratic mixed convection, magnetohydrodynamics, diffusion of nanoparticles and liquid hydrogen flow around a wedge. Highly coupled nonlinear partial differential equations (NPDEs) and boundary constraints have been used to model the flow problem, which are then transformed into a dimensionless set of equations utilizing non-similar transformations. Further, a set of NPDEs would be linearized with the help of Quasilinearization technique, and then, the linear partial differential equations are transformed into a block tri-diagonal system through using implicit finite difference scheme, which is solved using Verga’s algorithm. The study findings were explored through graphs for the fluid velocity, temperature, concentration, nanoparticle volume fraction distributions and its corresponding gradients. One of the important results of this study is that the higher wedge angle values upsurge the friction between the particles of the fluid and the wedge surface. Rising Schmidt number declines the concentration distribution and enhances the magnitude of Sherwood number. Nanofluid’s temperature increases with varying applied magnetic field. The present study has notable applications in the designing and manufacturing of wedge-shaped materials in space aircrafts, construction of dams, thermal systems, oil and gas industries, etc.

FORMATION OF CRUSHING ZONE AT THE LEVEL OF TAMPING IN THE CONDITIONS OF MASS EXPLOSIONS

The purpose of the work is to study the sequence of formation of the fracture zone in the area of the array above the ends of the system of adjacent charges in connection with the technological parameters of their mutual location. The task of works is the analytically substantiate the dependence of the value of the undamaged area of the array at the level of the bottomhole on the parameters of the system of downhole charges, taking into account the phenomenon of the edge effect. Research results. Data on the dimentions of the part of the massif in the lborewhole that does not participate in the mass deformation motion of the rock during the formation of adjacent downhole funnels are obtained. It is assumed that this area between adjacent charges is the source of the oversized fraction. Originality. The process of formation of the destroyed zone in space above the end of the boreholeis considered step by step: generation of the shock wave front, the symmetry of which is close to spherical, formation of the loosenning funnel system in the second stage, which does not adjacent charges of the total front of the stress wave from the explosion of downhole charges detonated from their bottom. Behind him moves the deformation front of a complex structure. It is assumed that this front in the system of two adjacent charges acquires a shape similar to a vertical wedge inverted by the base towards the free surface. The expected result of such a step-by-step deformation process is the desired degree of crushing of the rock mass at the level of the tamping. Conclusions and practical implications. Theoretically and calculatedly obtained and recommended rational parameters of the location of the system of well charges of limited length to reduce the size of the non-destructive region of the rock mass at the level of the tamping, which improves the design of mass explosions in mountain slopes.

Effects of core characteristics on seepage through earth dams

In this research, SEEP2D and SEEP/W numerical models are used to simulate seepage through earth dams with internal cores. In order to evaluate the two models' performance, they were compared in cases with no, vertical, and wedge-shaped cores. SEEP/W was then used to study further cases due to its accuracy in drawing the phreatic line within the core zone. The effect of the core's characteristics on the amount of discharge, and the phreatic line's levels at the core's upstream and downstream faces were investigated. Four core types – vertical, wedge-shaped, upstream inclined, and downstream inclined – were considered. Different hydraulic conductivities, upper widths, and core slopes were also evaluated. The wedge-shaped core is the most effective of those investigated in reducing seepage discharge and the phreatic line's level at the core's downstream face, the vertical core came second. Design equations are provided for all the core shapes considered in the study.

Mixed convection flow of a hybrid nanofluid past a vertical wedge with thermal radiation effect

Purpose The purpose of this paper is to numerically study the problem of mixed convection flow of a hybrid nanofluid past a vertical wedge with thermal radiation effect. Design/methodology/approach The governing nonlinear partial differential equations are transformed into a system of ordinary differential equations by a similarity transformation, which is then solved numerically through the function bvp4c from MATLAB for different values of the governing parameters. The solutions contain a mixed convection parameter λ that has a considerable impact on the flow fields. Findings It is found that the solutions of the ordinary (similarity) differential equations have two branches, upper and lower branch solutions, in a certain range of the mixed convection and several other parameters. To establish which of these solutions are stable and which are not, a stability analysis has been performed. The effects of the governing parameters on the fluid flow and heat transfer characteristics are illustrated in tables and figures. It is found that dual (upper and lower branch) solutions exist for both the cases of assisting and opposing flow situations. A stability analysis has also been conducted to determine the physical meaning and stability of the dual solutions. Practical implications This theoretical study is significantly relevant to the applications of the heat exchangers placed in a low-velocity environment and electronic devices cooled by fans. Originality/value The case of mixed convection flow of a hybrid nanofluid past a vertical wedge with thermal radiation effects has not been studied before, and hence all generated numerical results are claimed to be original and novel.

Mixed Bioconvective Flow Over a Wedge in Porous Media Drenched with a Nanofluid

A mathematical model is accentuated the mixed bioconvective flow on a vertical wedge in a Darcy porous medium filled with a nanofluid containing both nanoparticles and gyrotactic microorganisms. Thermophoresis and Brownian motion impacts are addressed to consolidate energy and concentration equations with passivelycontrolled boundary conditions. A mixed convective parameter for the whole regime of the mixed convective is appointed. The system of governing partial differential equations is converted into a non-similar set, which are then solved by an implicit finite difference method. By taking the impacts of the varying pertinent parameters, namely, the bioconvection nanofluids and wedge angle parameters in the entire mixed convection regime, the numerical results are analyzed graphically for the dimensionless the velocity, temperature, nanoparticle volume fraction and the density motile microorganisms profiles as well as the local Nusselt and motile microorganism numbers.