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This investigation deals with a comparison of suction/injection effect on flow, heat and mass transfer in porous media using a combined similarity-numerical solution. With this method of transformation, the governing transport PDEs are transformed into ODE and then solved numerically. The study reveals that suction/injection effect is more pronounce on the velocity distribution of a creeping flow (Darcy flow). The Darcy-Forchheimer flow has the steepest velocity curves due to non-linearity and has higher skin friction, heat and mass transfer rate when compared to the other porous media investigated.

Sonic boom reduction has been an urgent need to develop the future supersonic transport, because of the heavy damages of the noise pollution. This paper provides an active control method for the supersonic aircraft to reduce the sonic boom, wherein a suction slot near the leading edge and an injection slot near the trailing edge on the airfoil suction surface are opened, and the mass flow sucked in near the leading edge is equal to the mass flow injected near the trailing edge. The diamond and 566 airfoils are adopted as the baseline airfoil to verify the capability of the active control method, and the effects of the suction and injection location, the mass flow rate and the attack angle on the ground boom signature, the maximum overpressure, the drag coefficients and the ratio of lift to drag are studied in detail. The results show that the proposed active control method can significantly reduce the sonic boom, and the reduction of the sonic boom intensity is more sensitive to the injection near the trailing edge than the suction near the leading edge. Applying this active control method to the diamond (NACA0008) airfoil, when the mass flow rate is 6.5 kg/s(7.5 kg/s), the value of maximum positive overpressure is decreased by 12.87%(12.85%), the value of maximum negative overpressure is decreased by 33.83%(56.77%) and the drag coefficient is decreased by 9.50%(10.96%). It can be seen that the method proposed in this paper has great benefits in the reduction of sonic boom and provides a useful reference for designing a new generation of lower sonic boom supersonic aircraft.

The steady free convective boundary layer viscous fluid flow and heat transfer towards the moving flat plate is investigated. It is important to study the fluid flow and heat transfer problems in the presence of suction and injection effects due to an extensive variety of applications in engineering and industry. Thus, the main objective of the present study is to analyse the impacts of the suction and injection parameter on the velocity and temperature of the fluid as well as the skin friction and the Nusselt number coefficients. The problem has coupled partial differential equations which are converted into ordinary differential equations by employing similarity transformation and adopting of the strong wall suction. The ordinary differential equations thus obtain are handled numerically by utilizing Maple software simulation. The main findings concerning the behaviours of velocity and temperature against various values of the emerging physical parameter such as suction/injection are presented clearly in this numerical examination via graphical illustrations whose physical explanation are discussed thoroughly based on a strong theoretical basis. Furthermore, skin friction and Nusselt number results are studied at different values of pressure gradient. The detail geometry reveals that the velocity and temperature of the fluid decreases with increase of suction/injection parameter. Both skin friction coefficient and Nusselt number decreases with an increase of suction/injection parameter.

In this article, the mass and heat transfer flow of Ag–kerosene oil nanofluid over a cone under the effects of suction/injection, magnetic field, thermophoresis, Brownian diffusion, and Ohmic-viscous dissipation was examined. On applying the suitable transformation, PDEs directing the flow of nanofluid were molded to dimensionless ODEs. The solution of the reduced boundary value problem was accomplished by applying Runge–Kutta–Fehlberg method via shooting scheme and the upshots were sketched and interpreted. The values of shear stress and coefficients of heat and mass transfer were attained for some selected values of governing factors. The obtained results showed that when the amount of surface mass flux shifts from injection to the suction domain, the heat and mass transfer rate grew uniformly. However, they have regularly condensed with the rise in the magnitude of the magnetic field and particle volume fraction. Several researches have been done using cone-shaped geometry under the influence of various factors affecting the fluid flow, yet, there exists no such investigation that incorporated the response of viscous-Ohmic dissipation, heat absorption/generation, suction/blowing, Brownian diffusion, and thermophoresis on the hydro-magnetic flow of silver-kerosene oil nanofluid over a cone.

A theoretical study on the asymptotic suction/injection magnetohydrodynamic flow as a result of a uniform freestream couple stress fluid flowing over a flat surface is undertaken in the current study. It is targeted to obtain exact flow and temperature solutions representing the permeable couple stress fluid flow. Analytical expressions are extracted to derive interesting engineering tools such as momentum layer thickness, thermal layer thickness, wall shear stress, and heat transfer rate. The physical parameters leading to the existence of wall suction/injection solutions are determined with their thresholds. Momentum and thermal layer analysis from the present results clearly reveal how they are influenced by the presence of electrically conducting couple stress fluid. Further flow studies of similar kind will certainly benefit from the presented formulae.

The mathematical model responsible for fully developed laminar transient flow formation between the gaps of two stationary concentric porous tubes due to the imposition of azimuthal pressure gradient (Dean flow) is solved semi-analytically. The tubes walls are porous so that a radial flow can be superimposed. The solution of the momentum and continuity equations are obtained semi-analytically by using the combination of Laplace transform technique and a Laplace inversion method called Riemann sum approximation method. The solutions for skin friction at [Formula: see text] (outer surface of the inner porous tube) and [Formula: see text] (inner surface of the outer porous tube) are presented. The impact of suction/injection parameter and the ratio of the radii of the tubes are examined for the velocity profile and skin friction. Results show that the velocity profile decreases with increase in suction/injection parameter for various values of time, [Formula: see text] and at large value of time, ([Formula: see text]), the velocity and the skin friction attain a steady state.

Manufacturing of modern coating materials doped with magnetic nanoparticles has arisen as an exciting new area of materials processing fluid dynamics. Methanol is primarily used in chemical manufacturing, specialized vehicles fuel, energy carrier, as an antifreeze in pipelines, in wastewater treatment plant, and many more. In this article, a mathematical model is therefore developed to study crosswise flow of methanol-based ferromagnetic fluid through a permeable medium with suction/injection effects. Temperature-dependent viscosity is taken with Reynolds exponential model. The Tiwari–Das and Maxwell–Garnett nanofluid models are used, which alters the electrical conductivity, density, and thermal conductivity properties with nanoparticle volume fraction. The two-dimensional mass, momentum, and energy equations are normalized into nonlinear system comprising ordinary differential equations via appropriate similarity transformations. The solution of the emerging physical problem is attained by shooting scheme in MATLAB symbolic software. Validation of the results is presented through comparison with previously reported literature in the limiting sense. The influence of pertinent parameters on the flow and heat transfer characteristics is revealed through graphs. It is found that velocity profiles are suppressed with greater magnetic parameter and porosity parameters but temperature profile is enhanced. Velocity and temperature profiles for injection case are higher when compared with the suction phenomenon. Shear stress at the wall is decreased with volume fraction. Heat transfer gradient at the wall is significantly enhanced with volume fraction.

This article analyses the unsteady hydromagnetic free convection flow near impulsive as well as accelerated motion of the infinite vertical porous plate. The governing momentum and energy partial differential equations exhibiting the physics of the flow formation are presented. Using suitable dimensionless parameters, the equations are transformed to their corresponding dimensionless form and solved exactly in the Laplace domain using the well-known Laplace transform technique. However, the Riemann-sum approximation method is used to invert the solution from the Laplace domain to time domain due of the complexity of the solutions obtained in the Laplace domain. The effect of various pertinent parameters such as suction/injection, Hartmann number, Grashof number, and Prandtl number is discussed with the aid of line graphs.

This article describes the effects of Joule heating and chemical reaction on unsteady MHD mixed convective micropolar fluid over a stretching sheet in presence of radiation, non-uniform heat source and porous medium. The arising non-linear coupled partial differential equations are reduced to a set of coupled non-linear ordinary differential equations and then solved numerically by using the Runge– Kutta–Fehlberg fourth–fifth order method along shooting technique. The graphical and tabular results elucidate the influence of different non-dimensional governing parameters on the velocity, temperature and concentration fields along with the wall friction, local Nusselt and Sherwood numbers. We found the dual nature of the solutions for suction and injection cases. A good agreement of the present results has been observed by comparing with the existing literature results.

The theoretical study of laminar boundary layer flows of a non-Newtonian fluid past a stretching sheet in an embedded porous medium in the presence of suction/injection is of significant importance in the crystal growing, geothermal, metallurgical, polymer extrusion and several other technological processes. Casson fluid model is one such fluid model used to characterize the behaviour of non-Newtonian fluids. The present article discusses the Casson fluid flow past a permeable stretching sheet in the presence of mass transpiration. The physical problem is modelled into a system of nonlinear partial differential equations which are analytically solved by transforming them into nonlinear ordinary differential equations with constant coefficient by means of similarity transformations. The analysis reveals the effect of Casson parameter on the velocity boundary. In fact, the increasing Casson parameter results in the suppression of velocity boundary. It is found that the skin friction coefficient decreases with the decreasing values of Casson parameter. The effects of Darcy drag force and the mass transpiration are also analyzed by means of various plots.

This research work is focused on the effects of combined heat and mass transfer on MHD stagnation point flow of Carreau nanaofluid embedded in porous medium with heat source. Thermal radiation and chemical reaction are also taken into account. The governing non-linear PDEs are transformed into a set of non-linear coupled ODEs which are then solved numerically by using the Runge– Kutta–Fehlberg fourth–fifth order method along shooting technique. The graphical and tabular results elucidate the influence of different non-dimensional governing parameters on the velocity, temperature and concentration fields along with the wall friction, local Nusselt and Sherwood numbers. We found the dual nature of the solutions for suction and injection cases. A good agreement of the present results has been observed by comparing with the existing literature results.

In this paper, the hydromagnetic stagnation point flow and temporal stability of Fe3O4-water ferrofluid over a convectively heated permeable stretching/shrinking sheet is theoretically investigated. The model equations of momentum and energy balance are obtained and transformed into ordinary differential equations using appropriate similarity variable. Using shooting method together with Runge-Kutta-Fehlberg numerical scheme the model nonlinear boundary value problem is tackled numerically. Pertinent results with respect to the basic steady flow velocity, temperature, skin friction and Nusselt number are obtained graphically and in tabular form. It is found that a critical value of shrinking parameter (λc) exists below which no real solution can be found. In addition, dual solutions (upper and lower branch) are observed for a range of shrinking/stretching parameter (λc

In this investigation, the heat and mass transfer characteristics in boundary layer flow about a stretching sheet in a porous medium filled with TiO2 – water and Al2O3 – water-based nanofluids, in ...

Effect of suction/injection on the rate of entropy generation of third grade fluid with convective cooling is analysed in this work. The highly non-linear boundary value problems obtained from the governing equations are solved by Adomian decomposition method (ADM). Some plots are presented to explain the influence of pertinent parameters on fluid motion, temperature, entropy generation and irreversibility ratio. From the results it is shown that suction/injection and third grade fluid parameters reduce fluid velocity across the channel, and increase in suction/injection parameter enhances fluid temperature while convective cooling parameter reduces it. Entropy generation is enhanced by suction/injection parameter at the lower wall but reduces it at the upper wall

The present work is dedicated to the analytic analysis of the non-similar wall jet flows subject to various suction/injection profiles for the 1st time. To this end, it is employed regular perturbation technique to expand the solution about the Glauert origin. We have propagated the perturbed field up to the 15th order to identify the compatibility of the technique with the problem of interest as well as to explore some important features associated with the various suction/injection profiles. In the case of suction, the maximum normalized shear stress at the wall evolves as the exponent of the suction profiles varies; afterwards, a decrease in the quantity is expected so as to eventually annihilate the entire jet. Similarly, in the injection case, the exponent of the injection profiles plays a core role in the evolution of the normalized shear stress at the wall, the universal distance in which the quantity becomes zero and the recovery of the quantity after this critical location.

An unsteady double diffusive mixed convection boundary layer flow over a vertically stretching sheet in the presence of suction/injection is investigated in this paper. The governing partial differential equations are reduced by applying suitable transformations to a set of nonlinear ordinary differential equations, which is solved by the Keller box method. The influence of various flow parameters on the velocity, temperature, and species concentration profiles of the fluid is studied. The effect of some problem parameters on the skin friction coefficient in the presence of suction/injection is considered.

In this study, numerically analysed the Falkner-Skan equation in the two-dimensional laminar flow past a moveable wedge for a Newtonian fluid with suction/injection is investigated through Matlab environment. The boundary conditions are scrutinized and applied in this equation for different conditions. The simultaneous effect of the parameter which used to measure the pressure gradient along x-axis (β), velocity ratio between the wedge and mainstream (λ), suction and injection are inspected on the momentum boundary layer thickness or dimensionless velocity profile.

This work studies the time-dependent convective flow of non-Newtonian power-law fluid by vertical plate. Fluid flow is studied in the presence of thermal radiation. The Buongiorno model is employed to describe the features of nanofluid. Entropy generation and Bejan number are calculated. The flow, temperature and concentration are given by the system of partial differential equations (PDE’s). The system of PDE’s is transformed into dimensionless form by transformation and then solve implementing finite difference technique. Special emphasis is given to the outcomes of Prandtl number, Reynolds number, Eckert number, radiation parameter, thermophoresis, Brownian parameter, and Schmidt number. Velocity, temperature, concentration, skin friction, Sherwood and Nusselt numbers are graphically analyzed. Graphical results show that velocity of fluid enhanced for high Grashof number while shows opposite behavior for Reynold number. For the high estimation of the thermophoresis parameter and Brownian motion parameter temperature and concentration increase. For the higher value of the radiation parameter, the irreversibility of fluid particles increases while the Bejan number decreases.