Among several indicators for river engineering sustainability, the longitudinal dispersion coefficient ( Kx) is the main parameter that defines the transport of pollutants in natural streams. Accurate estimation of Kx has been challenging for hydrologists due to the high stochasticity and non-linearity of this hydraulic-environmental parameter. This study presents a new hybrid machine learning (ML)

Purpose The purpose of this study is to analyze the influence of the main physical–numerical parameters in the computational evaluation of natural convection heat transfer rates in isothermal flat square plates in the laminar regime. Moreover by experimentally validate the results of the numerical models and define the best parameter settings for the problem situation studied. Design/methodology/approach

Purpose The lattice Boltzmann simulation of fluid flow in partial porous geometries with curved porous-fluid interfaces has not been investigated yet. It is mainly because of the lack of a method in the lattice Boltzmann framework to model the hydrodynamic compatibility conditions at curved porous-fluid interfaces, which is required for the two-domain approach. Therefore, the purpose of this study

Purpose The current investigation is communicated to analyze the characteristics of squeezed second grade nanofluid flow enclosed by infinite channel in the existence of both heat generation and variable viscosity. The leading non-linear energy and momentum PDEs are converted into non-linear ODEs by using suitable analogous approach. Design/methodology/approach Then the acquired non-linear problem

Purpose This paper aims to simulate the nanofluid forced convection in a microchannel. According to the results, at high Reynolds numbers and higher nanofluid volume fractions, an increase in the rib height and slip coefficient further improved the heat transfer rate. The ribs also affect the flow physics depending on the Reynolds number so that the slip velocity decreases with increasing the nanofluid

Purpose This study aims to propose the parametric-guiding algorithm, the complex-root (CR) tunneling algorithm and the method that integrates both algorithms for the heat and fluid flow (HFF) community, and apply them to nonlinear Bratu’s boundary-value problem (BVP) and Blasius BVP. Design/methodology/approach In the first algorithm, iterations are primarily guided by a diminishing parameter that

Research on turbulent drag reduction has been limited owing to the limitations of existing parameters used for the identification of vortex structures. As a new and more suitable vortex parameter, Liutex provides a novel research method for turbulence control. We used a channel with a transverse groove structure as the research model and employed large-eddy simulation method based on Liutex to study

Purpose The purpose of this paper is to investigate the effects of Ha and the Nanoparticles (NP) volume fraction over the irreversibility and heat transport in Darcy–Forchheimer nanofluid saturated lid-driven porous medium. Design/methodology/approach The present paper highlights entropy generation because of mixed convection for a lid-driven porous enclosure filled through a nanoliquid and submitted

Purpose The purpose of this study is to analyze the disturbances in a two-dimensional nonlocal, micropolar elastic medium under the dual-phase-lag model of thermoelasticity whose surface is subjected to an inclined mechanical load. The present study is carried out under the influence of gravity. Design/methodology/approach The normal mode technique is used to obtain the exact expressions of the physical

Purpose This paper aims to compare the performance of flow pulsation versus flow stirring in the context of mixing of a passive scalar at moderate Reynolds numbers in confined flows. This comparison has been undertaken in two limits: diffusion can be neglected as compared to convection (very large Peclet) and diffusion and convection effects are comparable. The comparison was performed both in terms

Purpose The purpose of this paper is to study the soot formation and evolution by using this newly developed Lagrangian particle tracking with weighted fraction Monte Carlo (LPT-WFMC) method. Design/methodology/approach The weighted soot particles are used in this MC framework and is tracked using Lagrangian approach. A detailed soot model based on the LPT-WFMC method is used to study the soot formation

Purpose This study aims to analyze entropy generation and magnetohydrodynamic (MHD) natural convection of hybrid nanofluid in a square cavity, with a heated elliptical block placed at the center, in presence of a periodic-variable magnetic field. Design/methodology/approach In this paper, simulations were performed with a FORTRAN home code. The numerical methodology used to solve Navier–Stokes, energy

Purpose The design of a space launcher requires some considerations about the unsteady loads and heat transfer occurring at the base of the structure. In particular, these phenomena are predominant during the early stage of the flight. This paper aims to evaluate the ability of the unstructured, high order finite-volume CFD solver FLUSEPA, developed by Airbus Safran Launchers, to accurately describe

Purpose This study aims to satisfy the thermal management of gallium nitride (GaN) high-electron mobility transistor (HEMT) devices, microchannel-cooling is designed and optimized in this work. Design/methodology/approach A numerical simulation is performed to analyze the thermal and flow characteristics of microchannels in combination with computational fluid dynamics (CFD) and multi-objective evolutionary

Based on the analysis of the entropy condition scheme formulation, the accuracy order comes from initial value interpolation and flux reconstruction. Following the limiters of the traditional second-order Total Variation Diminishing scheme, higher accuracy order and non-oscillatory nature are retained with a newly proposed smoothness threshold method. Then, the scheme using the solution formula method

Purpose This study aims to use the thermal non-equilibrium approach to inquire the entropy production and conjugate natural heat exchange in a porous medium. Entropy generation is studied separately for the solid matrix and the hybrid nanoliquid. Design/methodology/approach The characteristic equations are unraveled by applying the finite element method. Mathematical relations are used to calculate

Purpose This study aims to focus on second grade fluid flow over a rotating disk in the presence of chemical reaction. Uniform magnetic field is also taken into account. Because of the smaller magnetic Reynolds number, induced magnetic field is negligible. Heat equation is constructed by considering heat source/sink. Design/methodology/approach Suitable variables are used to transform nonlinear partial

Purpose The purpose of this study is to use the method of lines to solve the two-dimensional nonlinear advection–diffusion–reaction equation with variable coefficients. Design/methodology/approach The strictly positive definite radial basis functions collocation method together with the decomposition of the interpolation matrix is used to turn the problem into a system of nonlinear first-order differential

Purpose This paper aims to analyze the propulsive performance of small-amplitude pitching foils at very high frequencies with double objectives: to find out scaling laws for the time-averaged thrust and propulsive efficiency at very high frequencies; and to characterize the Strouhal number above which the effect of turbulence on the mean values cannot be neglected. Design/methodology/approach The thrust

Purpose The purpose of this paper is to describe an extension of the boundary element method (BEM) and the dual reciprocity boundary element method (DRBEM) formulations developed for one- and two-dimensional steady-state problems, to analyse transient convection–diffusion problems associated with first-order chemical reaction. Design/methodology/approach The mathematical modelling has used a dual reciprocity

Purpose The purpose of this study is to numerically investigate the confined single-walled carbon nanotube-water nanofluid jet impingement heating of a cooled surface with a uniform heat flux in the presence of a porous layer. The analysis of the convective heat transfer mechanism is introduced considering the buoyancy force effect under local thermal non-equilibrium conditions. Design/methodology/approach

Inspired by the animal upper digestive tract, a unique soft-elastic reactor (SER) has recently been researched whose mixing phenomena should be further investigated. Numerical simulation is an excellent method with which to explore the phenomena in SERs for a large number of conditions. It may also offer insights into the ways of effective mixing in this kind of reactor. The mixing processes in 2D

Operation of heavy-duty machines leads to an observation that seals in hydraulic cylinders are frequently subjected to thermal degradation. The basis of this research is the previously proven thesis that the temperature of the liquid in the cylinder and the cylinder itself may significantly differ from the temperature of the liquid in the system and in the tank, thus enabling the temperature in the

In biodiesel production by trans-esterification, one of the essential compound is glycerin. Global glycerin production is increasing significantly, projecting a global value reduction for glycerol. Consequently the scientific community had been encouraged to investigate converting glycerol into more valuable products. In this research, the primary sources and processes of biodiesel production are surveyed

Purpose This paper aims to examine the Cu-Al2O3/water hybrid nanofluid flow over a shrinking sheet in the presence of the magnetic field and dust particles. Design/methodology/approach The governing partial differential equations for the two-phase flow of the hybrid nanofluid and the dust particles are reduced to ordinary differential equations using a similarity transformation. Then, these equations

Purpose The purpose of this study is to investigate the Cattaneo-Christov double diffusion, multiple slips and Darcy-Forchheimer’s effects on entropy optimized and thermally radiative flow, thermal and mass transport of hybrid nanoliquids past stretched cylinder subject to viscous dissipation and Arrhenius activation energy. Design/methodology/approach The presented flow problem consists of the flow

Purpose The purpose of this study is to quantify the free convective heat transfer around a vertical cylindrical electronic component equipped with vertical fins representing an antenna, contained in a closed cavity maintained isothermal. Its cooling is provided via a water-based copper nanofluid whose volume fraction varies between 0% and 10%. Its effective viscosity and thermal conductivity are determined

Purpose This study aims to propose a new numerical method for solving non-linear partial differential equations on irregular domains. Design/methodology/approach The main aim of the current paper is to propose a local meshless collocation method to solve the two-dimensional Klein-Kramers equation with a fractional derivative in the Riemann-Liouville sense, in the time term. This equation describes

Purpose The purpose of this paper is to study the propagation of inhomogeneous waves in a partially saturated poro-thermoelastic media through the examples of the free surface of such media.. Design/methodology/approach The mathematical model evolved by Zhou et al. (2019) is solved through the Helmholtz decomposition theorem. The propagation velocities of bulk waves in partially saturated poro-thermoelastic

Purpose This paper aims to study the mixed convective process due to various dynamics, namely, inner rotating cylinders and upper-wavy wall movement for the first time. Design/methodology/approach The Galerkin finite element method together with the characteristic-based split scheme is applied to solve the governing system. Findings The main outcomes revealed that the direction of the rotation of the

Purpose The aims of this study is to numerically investigate the thermal phenomena during magnetohydrodynamic (MHD) free convection in an oblique enclosure filled with porous media saturated with Cu–Al2O3/water hybrid nanofluid and heated at the left wavy wall. The thermophysical phenomena are explored thoroughly by varying the amplitude (λ) and undulation (n) of the wavy wall and the inclination of

Purpose The system of equations for fractional thermo-viscoelasticity is used to investigate two-dimensional bioheat transfer and heat-induced mechanical response in human skin tissue with rheological properties. Design/methodology/approach Laplace and Fourier’s transformations are used. The resulting formulation is applied to human skin tissue subjected to regional hyperthermia therapy for cancer

Purpose This paper aims to introduce a new (3 + 1)-dimensional fourth-order integrable equation characterized by second-order derivative in time t. The new equation models both right- and left-going waves in a like manner to the Boussinesq equation. Design/methodology/approach This formally uses the simplified Hirota’s method and lump schemes for determining multiple soliton solutions and lump solutions

Purpose The purpose of this paper is to investigate the effects of irregular unsettling on the smoking model in form of the stochastic model as in the deterministic model these effects are neglected for simplicity. Design/methodology/approach In this research, the authors investigate a stochastic smoking system in which the contact rate is perturbed by Lévy noise to control the trend of smoking. First

Purpose The purpose of this paper is to perform numerical simulations based on the incompressible smoothed particle hydrodynamics (ISPH) method for thermo-diffusion convection in a hexagonal-shaped cavity saturated by a porous medium and suspended by a nano-encapsulated phase change material (NEPCM). Here, the solid particles are inserted into a phase change material to enhance its thermal performance