Purpose The reported mathematical models of gas–liquid flow in single snorkel Rheinstahl–Heraeus (SSRH) are based on the assumption of steady Ar-molten steel flow. The purpose of this paper is to develop a mathematical model to describe the unsteady turbulent flow (CO-Ar-molten steel) with nonequilibrium decarburization reaction. Design/methodology/approach On the base of the finite volume method,

Purpose This paper aims to develop a new (3 + 1)-dimensional Painlev´e-integrable extended Sakovich equation. This paper formally derives multiple soliton solutions for this developed model. Design/methodology/approach This paper uses the simplified Hirota’s method for deriving multiple soliton solutions. Findings This paper finds that the developed (3 + 1)-dimensional Sakovich model exhibits complete

Purpose Entropy generation in nanofluids with peristaltic scheme occupies a primary consideration in the sense of its application in clinical, as well as the industrial field in terms of improved thermal conductivity of the original fluid. Three-dimensional cylindrical configurations are the most realistic and commonly used geometries which incorporate most of the experimental equipment. In the current

Purpose This paper aims to use a fractional constitutive model with a nonlocal velocity gradient for replacing the nonlinear constitutive model to characterize its complex rheological behavior, where non-linear characteristics exist, for example, the inherent viscous behavior of the crude oil. The feasibility and flexibility of the fractional model are tested via a case study of non-Newtonian fluid

Purpose This study aims to explore the idea of solving the problem of squeezing nanofluid flow between two parallel plates using a novel mathematical method. Design/methodology/approach The unsteady squeezing flow is a coupled fourth-order boundary value problem with flow velocity and temperature as the desired unknowns. In the first step, the conditions that guarantee the existence of a unique solution

Purpose This paper aims to focus on the natural convective flow analysis of micropolar nanofluid fluid in a rectangular vertical container. A heated source is placed in the lower wall to generate the internal flow. In further assumptions, the left/right wall are kept cool, while the upper and lower remaining portions are insulated. Free convection prevails in the regime because of thermal difference

Purpose This study/paper aims to deal with thermal convection and entropy production of a ferrofluid in an enclosure having an isothermally warmed solid body placed inside. It should be noted that this research deals with a development of passive cooling system for the electronic devices. Design/methodology/approach The domain of interest is a square chamber of size L including a rectangular solid

Purpose The purpose of this paper is to determine both analytically and numerically the kink solutions to a new one-dimensional, viscoelastic generalization of Burgers’ equation, which includes a non-linear constitutive law, and the number of kinks as functions of the non-linearity and relaxation parameters. Design/methodology/approach An analytical procedure and two explicit finite difference methods

Purpose This paper aims to deal with characterisation of the thermal performance of a hybrid tubular and cavity solar thermal receiver. Design/methodology/approach The coupled optical-flow-thermal analysis is carried out on the proposed receiver design. Modelling is performed in two and three dimensions for estimating heat loss by natural convection for an upward-facing cavity. Heat loss obtained in

Purpose The purpose of this paper is to investigate the immiscible two-layer heat fluid flows in the presence of the electric double layer (EDL) and magnetic field. The effects of EDL, magnetic field and the viscous dissipative term on fluid velocity and temperature, as well as the important physical quantities, are examined and discussed. Design/methodology/approach The upper and lower regions in

Purpose This paper aims to present a numerical study on the natural convection, which operates either as an evaporator or condenser unit of the heat pump system to pre-cool and pre-heat the ambient fresh air. Design/methodology/approach This study focuses on natural air cooling or heating within the air channel considering the double skin configuration. Particular focus is given to the analysis of

Purpose This study aims to present a numerical analysis of the behavior of the electric field and flow field characteristics under electrohydrodynamics (EHD) force. The influence of the jet airflow under the EHD force is investigated when it impacts the inclined flat plate. Design/methodology/approach The high electrical voltage and angle of an inclined flat plate are tested in a range of 0–30 kV and

Purpose The purpose of this paper is to evaluate the temperature, the Dirichlet conditions have been considered to the parallel horizontal plates. The model of generalized Brinkman-extended Darcy with the Boussinesq approximation is considered and the governing equations are computed by COMSOL multiphysics. Design/methodology/approach In the current study, the thermodynamic irreversible principle is

Purpose The purpose of this paper is to know the influence of heat generation/absorption and slip effects on heat and mass transfer flow of carbon nanotubes – water-based nanofluid over a rotating disk. Two types of carbon nanotubes, single and multi-walled, are considered in this analysis. Design/methodology/approach The non-dimensional system of governing equations is constructed using compatible

Purpose The purpose of this paper is to investigate natural convection in a porous wavy-walled enclosure that is including a cylinder cavity in the middle of it and filled with a hybrid nanofluid contains 1-Butanol as the base fluid and MoS2–Fe3O4 hybrid nanoparticles. Design/methodology/approach The domain of interest is bounded by constant temperature horizontal corrugated surfaces and isothermal

Purpose Paper aims to present problem of aerodynamic heating of a metallic heat shield. The key elements of this construction are metallic layers of superalloy honeycomb, which significantly increase the structure’s resistance to impact. Paper describes the problem of influence of damage size on increase of thermal load. Design/methodology/approach Numerical analysis was performed in a non-commercial

Purpose Generally, in computational thermofluid dynamics, the thermophysical properties of fluids (e.g. viscosity and thermal conductivity) are considered as constant. However, in many applications, the variability of these properties plays a significant role in modifying transport characteristics while the temperature difference in the boundary layer is notable. These include drag reduction in heavy

Purpose This study aims to investigate the insights of soot formation such as rate of soot coagulation, rate of soot nucleation, rate of soot surface growth and soot surface oxidation in ethylene/hydrogen/nitrogen diffusion jet flame at standard atmospheric conditions, which is very challenging to capture even with highly sophisticated measuring systems such as Laser Induced Incandescence and Planar

Purpose The purpose of this study is analysis of the natural convection and entropy production in a two-dimensional section of the considered heat exchanger. For this purpose, the lattice Boltzmann method which is equipped with Bhatnagar–Gross–Krook model is used. This model proposes a significant accurate prediction for thermal and hydro-dynamical behaviors over free convection phenomenon. The heat

Purpose Convection is one of the main heat transfer mechanisms in both high to low temperature media. The accurate convection heat transfer coefficient (HTC) value is required for exact prediction of heat transfer. As convection HTC depends on many variables including fluid properties, flow hydrodynamics, surface geometry and operating and boundary conditions, among others, its accurate estimation

Purpose The purpose of this paper is to examine the electro-magnetohydrodynamic behavior of a third-grade non-Newtonian fluid, flowing between a pair of parallel plates in the presence of electric and magnetic fields. The flow medium between the plates is porous. The effects of Joule heating and viscous energy dissipation are studied in the present study. Design/methodology/approach A semi-analytical/numerical

Purpose The purpose of this study is to explore the heat transfer enhancement in copper–water nanofluid flowing in a diagonally vented rectangular enclosure with four discrete heaters mounted centrally on the sidewalls and a square-shaped embedded heated block in the influence of a static magnetic field. Design/methodology/approach Four discrete heaters are mounted centrally on each sidewall of the

Purpose In this paper, the uncertainties important components and the structure status are obtained by using the condition monitoring, expert groups and multiple membership functions by creating a fuzzy system in MATLAB software. Design/methodology/approach In the form of fuzzy type, the average structural safety must be followed to replace the damages or to absolutely control the decision-making.

Purpose This study aims to analyze the unsteady flow of hybrid Cu-Al2O3/water nanofluid over a permeable stretching/shrinking disc. The analysis of flow stability is also purposed because of the non-uniqueness of solutions. Design/methodology/approach The reduced differential equations (similarity) are solved numerically using the aid of bvp4c solver (Matlab). Two types of thermophysical correlations

Purpose The purpose of this study is to analyze the two-dimensional disturbances in a nonlocal, functionally graded, isotropic thermoelastic medium under the purview of the Green–Lindsay model of generalized thermoelasticity. The formulation is subjected to a mechanical load. All the thermomechanical properties of the solid are assumed to vary exponentially with the position. Design/methodology/approach

Purpose The purpose of this paper is to study the homoclinic breather waves, rogue waves and multi-soliton waves of the (2 + 1)-dimensional Mel’nikov equation, which describes an interaction of long waves with short wave packets. Design/methodology/approach The author applies the Hirota’s bilinear method, extended homoclinic test approach and parameter limit method to construct the homoclinic breather

Purpose The purpose of this paper is to solve the problem of a three-dimensional computational analysis for an elliptic-shaped cavity in a pipe under constant temperature. Design/methodology/approach The three-dimensional computational solution of governing equations was performed by using finite volume method with different temperature difference. Findings The parafin wax was chosen as a phase change

Purpose This study aims to present a numerical study on the flow and heat transfer performance of a water-cooled tube with protrusions in different geometrical parameters. Design/methodology/approach A new type of enhanced heat exchanger tube is designed. Protrusions are formed on the inner surface of the tube by mechanical expansion, compression and other processing methods. A three-dimensional numerical

Purpose This paper aims to establish a mathematical model for water-flooding considering the impact of fluid–solid coupling to describe the process of development for a low-permeability reservoir. The numerical simulation method was used to analyze the process of injected water channeling into the interlayer. Design/methodology/approach Some typical cores including the sandstone and the mudstone were

Purpose The purpose of this paper is to study the unsteady ferrofluid flow with a hot source helix inside a cavity under the impacts of a variable magnetic field by using the incompressible smoothed particle hydrodynamics method. Design/methodology/approach The governing equations are formulated by considering the basics of the magnetohydrodynamic and ferrohydrodynamics. Different locations of a variable

Purpose The purpose of this study is to use an incompressible smoothed particle hydrodynamics (ISPH) method for simulating buoyancy ratio and magnetic field effects on double diffusive natural convection of a cooper-water nanofluid in a cavity. An open pipe is embedded inside the center of a cavity, and it is occupied by solid particles. Design/methodology/approach The dimensionless governing equations

Purpose This study aims to numerically investigate the flow features and mixing/combustion efficiencies in a turbulent reacting jet in cross-flow by a hybrid Eulerian-Lagrangian methodology. Design/methodology/approach A high-order hybrid solver is employed where, the velocity field is obtained by solving the Eulerian filtered compressible transport equations while the species are simulated by using

Purpose This study aims to explore an active control strategy for attenuation of in-line and transverse flow-induced vibration (FIV) of two tandem-arranged circular cylinders. Design/methodology/approach The control system is based on the rotary oscillation of cylinders around their axis, which acts according to the lift coefficient feedback signal. The fluid-solid interaction simulations are performed

Purpose This study aims to deal with the numerical investigation of ferrofluid flow and heat transfer inside a right-angle triangular cavity in the presence of a magnetic field. The vertical wall is partially heated, whereas other walls are kept cold. The effects of thermal radiation are included in the analysis. The governing equations including continuity, momentum and energy equations are converted

Purpose This paper aims to report theoretical and numerical results for the problem of laminar axisymmetric flow of hybrid nanofluid over a permeable non-linearly stretching/shrinking sheet with radiation effect. Design/methodology/approach The numerical solutions of the arising boundary value problem are obtained using the function bvp4c from MATLAB for different values of the governing parameters

Purpose This paper aims to investigate the role of shapes of containers (nine different containers) on entropy generation minimization involving identical cross-sectional area (1 sq. unit) in the presence of identical heating (isothermal). The nine containers are categorized into three classes based on their geometric similarities (Class 1: square, tilted square and parallelogram; Class 2: trapezoidal

Purpose This study aims to explore magnetohydrodynamic (MHD) thermo-bioconvection of oxytactic microorganisms in multi-physical directions addressing thermal gradient, lid motion, porous substance and magnetic field collectively using a typical differentially heated two-sided lid-driven cavity. The consequences of a range of pertinent parameters on the flow structure, temperature, oxygen isoconcentration

Purpose The purpose of this paper is to describe the Lane–Emden equation by the fractal derivative and establish its variational principle by using the semi-inverse method. The variational principle is helpful to research the structure of the solution. The approximate analytical solution of the fractal Lane–Emden equation is obtained by the variational iteration method. The example illustrates that

Purpose This study aims to deal with the large eddy simulation (LES) of an ignition sequence and the resulting steady combustion in a swirl-stabilized liquid-fueled combustor. Particular attention is paid to the ease of handling the numerical tool, the accuracy of the results and the reasonable computational cost involved. The primary aim of the study is to appraise the ability of the newly developed

Purpose This study aims to investigate the flow behavior of aluminum oxide–water nanofluid with variable viscosity flowing through the microchannel parallel with the ground, with low aspect ratio. The study focuses on the first and second law analyses of Poiseuille flow using water as the base fluid with alumina nanoparticles suspended in it. Combined effects of thermal radiation, viscous dissipation

Purpose This study aims to develop a new (3 + 1)-dimensional Painlevé-integrable extended Vakhnenko–Parkes equation. The author formally derives multiple soliton solutions for this developed model. Design/methodology/approach The study used the simplified Hirota’s method for deriving multiple soliton solutions. Findings The study finds that the developed (3 + 1)-dimensional Vakhnenko–Parkes model exhibits

Purpose The purpose of this study is to present and demonstrate a numerical method for solving chemically reacting flows. These are important for energy conversion devices, which rely on chemical reactions as their operational mechanism, with heat generated from the combustion of the fuel, often gases, being converted to work. Design/methodology/approach The numerical study of such flows requires the

Purpose This study aims to propose the increase of heat dissipation requirements of modern electronic equipment and the fast development of micro-scale manufacturing technologies. The heat transfer mechanism is studied in-depth, especially for its pattern of secondary flow caused by the repeated inversion of centrifugal force. Effects of η on the frictional pressure drop and average Nusselt number

Purpose This study aims to investigate the flow and heat transfer of a hybrid nanofluid through an exponentially stretching/shrinking sheet along with mixed convection and Joule heating. The nanoparticles alumina (Al2O3) and copper (Cu) are suspended into a base fluid (water) to form a new kind of hybrid nanofluid (Al2O3-Cu/water). Also, the effects of constant mixed convection parameter and Joule

Purpose This study aims to investigate the flow impinging on a stagnation point of a shrinking cylinder subjected to prescribed surface heat flux in Al2O3-Cu/water hybrid nanofluid. Design/methodology/approach Using similarity variables, the similarity equations are obtained and then solved using bvp4c in MATLAB. The effects of several physical parameters on the skin friction and heat transfer rate

Purpose The discontinuous Galerkin finite element method (DGFEM) is very suited for realizing high order resolution approximations on unstructured grids for calculating the hyperbolic conservation law. However, it requires a significant amount of computing resources. Therefore, this paper aims to investigate how to solve the Euler equations in parallel systems and improve the parallel performance.

Purpose The purpose of this paper is the numerical investigation of the friction laws for incompressible flow in undulated channels, with emphasis on the applicability of the hydraulic diameter concept. A focal point of the study is the derivation of correlations to increase the accuracy of the hydraulic diameter approach. Design/methodology/approach Calculations are performed for laminar and turbulent

Purpose The purpose of this paper is to investigate a three-dimensional boundary layer flow with considering heat and mass transfer on a nonlinearly stretching sheet by using a novel operational-matrix-based method. Design/methodology/approach The partial differential equations that governing the problem are converted into the system of nonlinear ordinary differential equations (ODEs) with considering

Purpose Natural gas leak from underground pipelines could lead to serious damage and global warming, whose spreading in soil should be systematically investigated. This paper aims to propose a three-dimensional numerical model to analyze the methane–air transportation in soil. The results could help understand the diffusion process of natural gas in soil, which is essential for locating leak source

Purpose This study aims to investigate numerically the problem of conjugate conduction and mixed convection heat transfer of a nanofluid in a rotational/stationary circular enclosure using a two-phase mixture model. Design/methodology/approach Hot and cold surfaces on the wall or inside the enclosure (heater and cooler) are maintained at constant temperature of Th and Tc, respectively, whereas other

Purpose The purpose of this paper is to study the laminar boundary layer cross flow and heat transfer on a rotational stagnation-point flow over either a stretching or shrinking porous wall submerged in hybrid nanofluids. The involved boundary layers are of stream-wise type with stretching/shrinking process along the surface. Design/methodology/approach Using appropriate similarity variables the partial

Purpose The purpose of this study is to investigate the unsteady stagnation-point flow and heat transfer of fractional Maxwell fluid towards a time power-law-dependent stretching plate. Based on the characteristics of pressure in the boundary layer, the momentum equation with the fractional Maxwell model is firstly formulated to analyze unsteady stagnation-point flow. Furthermore, generalized Fourier’s

Purpose The pin fin is applied into a Lamilloy cooling structure which is broadly used in the leading edge region of the modern gas turbine vane. The purpose of this paper is to investigate effects of the layout, diameter and shape of pin fins on the flow structure and heat transfer characteristics in a newly improved Lamilloy structure at the leading edge region of a turbine vane. Design/methodology/approach

Purpose The purpose of this study is to numerically analyze the mixed convection and entropy generation in an annulus with a rotating heated inner cylinder for single-wall carbon nanotube (SWCNT)–water nanofluid flow using local thermal nonequilibrium (LTNE) model. An examination of the system behavior is presented considering the heat-generating solid phase inside the porous layer partly filled at

Purpose The purpose of this paper is to investigate thermally and hydrodynamically fully developed convection in a duct of rectangular cross-section containing a porous medium and fluid layer. Design/methodology/approach The Darcy–Brinkman–Forchheimer flow model is adopted. A finite difference method of second-order accuracy with the Southwell-over-relaxation method is deployed to solve the non-dimensional

Purpose The purpose of this study is to discuss the Darcy–Forchheimer nanoliquid bio-convection flow by stretching cylinder/plate with modified heat and mass fluxes, activation energy and gyrotactic motile microorganism features. Design/methodology/approach The proposed flow model is based on flow rate, temperature of nanomaterials, volume fraction of nanoparticles and gyrotactic motile microorganisms

Purpose This study aim to use the finite volume method to solve differential equations related to three-dimensional simulation of a solar collector. Modeling is done using ANSYS-fluent software program. The investigation is done for a photovoltaic (PV) solar cell, with the dimension of 394 × 84 mm2, which is the aluminum type and receives the constant heat flux of 800 W.m−2. Water is also used as the

Purpose The purpose of this paper is to study the reflection of plane waves in an initially stressed rotating thermoelastic diffusive medium with micro-concentrations and two-temperature. Design/methodology/approach A two-dimensional model of generalized thermoelasticity is considered. The governing equations are transformed into the non-dimensional forms using the dimensionless variables. Then, potential

Purpose The formulation of nonlinear convective non-Newtonian material is reported in this communication. Aspects of thermal radiation and heat source are taken into account for heat transport analysis. The novel stratifications (thermal and solutal) and convective conditions are considered simultaneously. The boundary-layer concept is implemented to simplify the complex mathematical expressions.

Purpose The purpose of this study is to perform a detailed review on the numerical modeling of multiphase and multicomponent flows in microfluidic system using phase-field method. The phase-field method is of emerging importance in numerical computation of transport phenomena involving multiple phases and/or components. This method is not only used to model interfacial phenomena typical to multiphase