Mixed Convection Flow Research Articles

Two-phase simulation of entropy optimized mixed convection flow of two different shear-thinning nanomaterials in thermal and mass diffusion systems with Lorentz forces

This research compares the momentum, thermal energy, mass diffusion and entropy generation of two shear thinning nanofluids in an angled micro-channel with mixed convection, nonlinear thermal radiation, temperature jump boundary condition and variable thermal conductivity effects. The RKF 45 approach was used to solve the Buongiorno nonlinear governing model. The effect of different parameters on the flow, energy, concentration, and entropy generating fields have been graphically illustrated and explained. The hyperbolic tangent nanoliquid has a better velocity than the Williamson nanofluid. The Williamson nanofluid has higher thermal energy and concentration than the hyperbolic tangent nanoliquid in the microchannel. The Grashof number, both thermal and solutal, increases the fluid flow rate throughout the flow system. The energy of the nanoliquid is reduced by the temperature jump condition, while the energy field of the nanoliquid is enhanced by the improving thermal conductivity value. The nanoliquids concentration rises as the Schmitt number rises. The irreversibility rate of the channel system is maximized by the variable thermal conductivity parameter.

Heat and mass transfer under MHD mixed convection in a four‐sided lid‐driven square cavity

AbstractThis paper investigates the heat and mass transfer under magnetohydrodynamic mixed convection flow of a binary gas mixture in a four‐sided lid‐driven square cavity. The enclosure's left wall is sinusoidally heated and acts as a source term, while the right wall functions as a sink. The cavity's horizontal walls are adiabatic and impermeable to mass transfer. The governing equations under Boussinesq approximation and stream function‐vorticity formulation are solved using the alternating‐direction‐implicit scheme, a finite‐difference method. The numerical scheme's consistency and stability are demonstrated using the matrix method. The MATLAB code is written, validated against some existing studies, and used to perform numerical simulations. The numerical solutions are graphically examined by visualizing the streamline, isotherm, and concentration contours for nondimensional parameters, such as Hartmann number , heat absorption or generation coefficient , Richardson number , and buoyancy ratio . The magnetic field modifies the temperature and concentration distribution in the cavity, depending on the convection mode. The magnetic field forces the fluid to stagnate in different regions of the cavity, depending on the mode of convection. It was found that the difference between the maximum and minimum temperature and concentration at the cavity's midpoint increases up to 13 and 10 times, respectively, in the natural convection compared with the forced convection. The average Nusselt number on the vertical walls of the cavity is maximum in natural convection in the absence of a magnetic field but reaches a minimum value at in forced and mixed convection. The average Sherwood number on the cavity's vertical walls decreases with the magnetic field in mixed and natural convection.

Chemical Reaction Effects on the Flow of Titanium Dioxide–Water in a Mixed Convective Nanofluid along an Inclined Plate in a Porous Medium

An inclined plate is being approached by a mixed convective boundary layer nanofluid flow of titanium dioxide–water through a porous medium. A numerical analysis has been done to investigate the effects of chemical reactions on the considered nanofluid flow. With the aid of a system of governing partial differential equations, a set of nonlinear ordinary differential equations for taking into consideration nanofluid flow have been derived using appropriate matching transformations. The Runge–Kutta method, as well as the Nachtsheim and Swigert Shooting method, is applied to numerically resolve the group of subsequent nondimensionalized equations. The associated numerical result was then successfully compared with the available published literature in a few unique, limited circumstances. Based on the considered nanofluid flow characteristics for heat as well as mass transfer, the effects of the Schmidt number, the permeability, and the chemical reaction parameters of the titanium dioxide–water nanofluid flow have been examined, assessed, and presented for velocity in conjunction with the local skin friction coefficient, temperature in conjunction with the local Nusselt number, as well as concentration in conjunction with the local Sherwood number. Numerical results reveal that the local Sherwood number Sh, as well as the local Nusselt number Nux, increase, whereas the local skin friction coefficient Cf decreases due to the increase in the chemical reaction parameter Krp.

Evolutionary design investigation applied to mixed convection heat transfer flows over semi-elliptical blocks inserted into a rectangular channel

Evolutionary design investigation applied to mixed convection heat transfer flows over semi-elliptical blocks inserted into a rectangular channel

Evolutionary design investigation applied to mixed convection heat transfer flows over semi-elliptical blocks inserted into a rectangular channel

Evolutionary design investigation applied to mixed convection heat transfer flows over semi-elliptical blocks inserted into a rectangular channel

Irreversibility analysis of mixed convection Jeffrey fluid flow between vertical parallel plates with an inclined magnetic field

Irreversibility analysis of mixed convection Jeffrey fluid flow between vertical parallel plates with an inclined magnetic field

Impact of heat source on mixed convection hybrid ferrofluid flow across a shrinking inclined plate subject to convective boundary conditions

Hybrid ferrofluids have exhibited enhanced heat transfer results in numerous applications. Industry demands like inclination sensors and solar water heaters give a new insight into heat transfer problems on the angle of inclination problems. Thus, this paper is motivated to analyse the effect of inclination angle towards mixed convection hybrid ferrofluid flow, including heat sources and convective boundary conditions, on a porous shrink surface. By utilising a similarity transformation, the intricate nature of the partial differential equations (PDEs) is simplified, transforming it into a set of ordinary differential equations (ODEs) and numerically solved in the bvp4c (MATLAB). A positive correlation was obtained between the current model and past researchers. Besides that, the increase in nanoparticle volume fraction improved the skin friction by approximately 14.79% and 15.00% for opposing and assisting flow regions, accordingly. Altering the inclination angle positively impacted growth by approximately 3.28% and 0.0068% on the skin friction and the heat transfer rate, accordingly. The inclusion of a heat source reduced the heat transfer rate by approximately 0.20% and 0.19% for both opposing and assisting flow regions, respectively. Meanwhile, a greater rise in heat transfer rate by approximately 174.48% when the Biot number, Bi rose.

Optimization of system parameters during conjugate mixed convective flow in a square domain with an oscillating spinning cylinder

A computational analysis has been executed to analyze the combined conduction-mixed convection heat transfer of a rotationally oscillating solid cylinder in a differentially heated square box filled with air. The conjugate mixed convective flow initiates the heat transfer process, where the left-side boundary is isothermally kept to a higher temperature, and the right-side boundary is maintained at a lower temperature. Conduction heat transfer takes place inside the solid cylinder. Navier-Stokes and heat energy conservation equations model the system in the dimensionless pressure-velocity formulation. All these equations are solved via the Galerkin finite element approach. Three different combinations of Grashof (103-105), Reynolds (32–316), and Richardson (0.1–10) numbers are examined to systematically investigate the variations of governing parameters on instantaneous Nusselt numbers and the respective time-averaged values along the hot wall. In each combination, the impacts of the oscillating amplitude and frequency and the variation of cylinder diameter are examined to perform the optimization study. Power spectrum analysis is also done using the Fast Fourier Transform in the frequency domain to visualize the principal frequency of the system. The instantaneous values of the Nusselt number exhibit a wavering pattern over time owing to the recurrent waning and waxing of the thermal boundary layer. For all the cases, the maximum diameter and oscillating amplitude of the cylinder are found to maximize the heat transfer. However, the optimized frequency of the oscillation strongly depends on the selection of the governing parameters. In addition, the principal thermal frequency of the system is determined to be independent of the oscillation frequency.

Flow control using hot splitter plates in the wake of a circular cylinder: A hybrid strategy

A novel and effective hybrid technique, which involves active surface heating strategies in conjunction with the use of passive splitter plates in the wake of the cylinder, is proposed. In this report, we present the results of a numerical investigation on the two-dimensional, laminar mixed convection flow over a circular cylinder with a hot rigid splitter plate attached to it on the wake side. A projection algorithm-based finite volume method is employed to obtain the solution of the coupled, nonlinear governing partial differential equations subjected to Courant–Friedrichs–Lewy conditions. The isothermal heating of the splitter plate under the influence of the gravity field generates an upward buoyancy force in the wake of the cylinder. For different length-to-diameter (L/D) ratios, the effect of heating on aerodynamic, wake, and heat transfer characteristics has been studied for a wide range of parameters; 75 ≤Re≤ 150, 0 ≤Ri≤ 1, and 0.5 ≤L/D≤ 1 at Pr = 0.7. It is observed that the hot splitter plate would bring about conspicuous changes such as asymmetry in the vortex shedding behind the cylinder at low Reynolds numbers. The outcomes demonstrate a notable improvement in convective heat transfer and drag, with gains of up to 7% and 15%, respectively. It is found that the rate of heat transfer and vortex shedding frequency decrease with an increase in L/D ratio. Correlations for the estimation of Strouhal number and Nusselt number have also been proposed which helps provide a more thorough understanding of thermal and aerodynamic features of the hybrid approach.

UNSTEADY MIXED CONVECTION HYDRO-MAGNETIC CASSON THERMO-DIFFUSION FLOW OF REACTING AND DISSIPATING FLUID WITH AN INCLINED MAGNETIC FIELD ALONG AN OSCILLATING SLANTED POROUS PLATE

A finite element numerical simulation is undertaken to explore the aspects of angled magnetic field and thermo-diffusion on an unsteady reacting mixed convection flow of hydro-magnetic Casson dissipating fluid with thermal radiation. The fluid streams across an oscillating tilted plate ingrained in a porous medium including time-altering temperature and concentration. The dimensionless flow, guiding partial differential equations along their associated initial and boundary conditions, are handled, enforcing an efficient finite element scheme. The key parameters affecting the velocity, temperature, and concentration profiles are comprehensively interpreted through graphical representations while the skin friction, heat transfer, and mass transfer rates are outlined via tables. The ultimate results of this study posted that the plate inclination angle, Casson parameter, and applied magnetic strengths are compelled to impede the fluid velocity and local skin friction, whereas the porosity parameter displays a reverse effect. The thermo-diffusion effect amplifies the fluid velocity and species concentration. It also supports that the Eckert number and heat source boost up the velocity and temperature profiles. Moreover, increasing radiation parameter and time crusade results in an upsurge in the Nusselt number. The chemical reaction quickens the Sherwood number, but it decays with the thermo-diffusion parameter. A comparative analysis between the current findings and existing research works in the literature demonstrates the results' precision and exactitude.

Dufour and Soret effects on unsteady MHD mixed convective flow across a stretching curved surface with thermal and velocity slip: A numerical study

Dufour and Soret effects on unsteady MHD mixed convective flow across a stretching curved surface with thermal and velocity slip: A numerical study

MHD Mixed Convection Flow and Heat Transfer due to an Inclined Stretching/Shrinking Sheet

MHD Mixed Convection Flow and Heat Transfer due to an Inclined Stretching/Shrinking Sheet

Aspects of Dual Simulation for Modified Thermal Flux Advances in Non‐Newtonian Reiner–Philippoff Fluid Flow past a Shrinking Plate Embedded in a Porous Medium

This study investigates the effects of non‐Newtonian Reiner–Philippoff fluids on porous media, particularly in the context of steady radiative mixed convection flow and heat transfer near a shrinking plate surface in the presence of magnetohydrodynamics (MHD). The mathematical model is constructed using PDEs and transformed into ODEs via similarity transformations, with numerical solutions obtained using MATLAB’s bvp4c function. The results demonstrate that boundary layer separation occurs slowest for dilatant fluids and fastest for pseudoplastic fluids, with Newtonian fluids exhibiting moderate separation rates. Thermal radiation and media porosity parameters are found to reduce heat transfer by approximately 0.95% and 0.02%, respectively, while accelerating boundary layer separation. Conversely, magnetic effects and suction parameters increase heat transfer by about 0.08% and 4.25%, respectively, enhancing both fluid velocity and temperature. The mixed convection parameter indicates the possibility of dual solutions, with the opposing flow favoring this phenomenon more than the assisting flow. The time‐based stability analysis reveals that the first solution is stable, whereas the second solution is unstable. These findings provide significant insights into the behavior and control of Reiner–Philippoff fluids in practical applications involving porous media and magnetic fields.

Impact of Cattaneo-Christov heat flux on mixed convection flow of a ternary hybrid (Cu-Al2O3-TiO2/H2O) nanofluid over an elongated sheet: A comparative analysis

Impact of Cattaneo-Christov heat flux on mixed convection flow of a ternary hybrid (Cu-Al2O3-TiO2/H2O) nanofluid over an elongated sheet: A comparative analysis

SPECTRAL ANALYSIS FOR ENTROPY GENERATION AND IRREVERSIBILITY ON NiZnFe2O4: ENGINE OIL BASED NANOFLUID IN POROUS MEDIUM

This study aims to investigate the impact of volume fraction on entropy generation in a melting stretching/shrinking sheet scenario, considering both first and second-order velocity slips. The investigation focuses on the mixed convective flow of a nanofluid in a porous medium comprising nickel-zinc ferrite and SAE 20W-40 motor oil, which is characterized by Society of Automotive Engineer. Ferrites possess exceptional resistance properties, a crucial consideration in microwave applications. The solution to the derived nondimensional flow governing differential equations is computed using the spectral local linearization method combined with a local non-similarity technique. An assessment of the error is performed to verify the convergence of the numerical approach utilized. A comparison to existing results for specific cases highlights a strong agreement. Various flow-influencing parameters are considered to investigate entropy production, Bejan number, velocity, temperature, heat transport, and skin friction characteristics. The outcomes are presented in graphical form for different parameter values. After simulation, it is perceived that the melting parameter and Darcy number disrupt the entropy by 35.94 and 2.21%, respectively, and enhance the heat transport rate by 27.71 and 2.72%, respectively. This work can be utilized in designing innovative materials for electronics and textiles, in environmental processes like groundwater movement and pollutant dispersion, and in the biomedical field like hyperthermia treatments, tissue engineering, and regenerative medicine.

Lattice Boltzmann Simulation of Mixed Convection Around a Heated Elliptic Block Cylinder within a Lid-driven Square Cavity

A numerical analysis of mixed convection flows and heat transfer in a square enclosure having a sliding wall containing an elliptical block heated by isothermal temperature has been carried out. The enclosure is full of air and cooling from its sides by a cold temperature, whereas the remaining walls of the enclosure are considered thermally insulated. The mixed convection impact is attained by the heating elliptic block and moving upper wall. The investigation of fluid’s hydrodynamic and thermal behavior was examined by using Lattice Boltzmann Method (LBM) at different locations and orientations of the interior elliptical block for Richardson number, Ri, varying from 0.01 to 100 while the Rayleigh number, Ra, is fixed at 104. The findings indicate that the temperature pattern and flow structure are very responsive to the position of the elliptical block and Richardson number. Also, it is found that the heat exchange is very important for the block placed vertically close to the left wall or horizontally close to the bottom wall. More precisely, for Ri = 0.01, by moving the vertical block from the center towards the vicinity of the left/ (the right) surface, the heat transfer rate increases from 5.44 to 11.06/(8.36) with an increase of 103.30%/(53.67%). On the other hand, it is noted that the horizontal elliptic block favors heat evacuation in comparison with the vertical one. This study’s real-world impact lies in the potential to improve our understanding and, consequently, design more efficient cooling systems for electronic devices.

Nanoparticle Shape Effects of Aligned Magnetohydrodynamics Mixed Convection Flow of Jeffrey Hybrid Nanofluid over a Stretching Vertical Plate

This study investigates the nanoparticle shape effects of aligned magnetohydrodynamics (MHD) mixed convection flow of Cu-Al2O3/water-EG Jeffrey hybrid nanofluid over a stretching vertical plate. Five different shapes of nanoparticles which are spherical, cylindrical, blades, bricks, and platelets are considered in this study. The governing equations in the form of Partial Differential Equations (PDEs) had been reduced to nonlinear Ordinary Differential Equations (ODEs) by using similarity transformation. The solver bvp4c in MATLAB software was applied to numerically solve the dimensionless governing equations towards the physical parameters which are aligned angle of magnetic field, interaction of magnetic field, mixed convection, Deborah number, volume fraction of nanoparticles, and nanoparticle shape factor. The effects of nanoparticle shapes and other relevant thermophysical parameters on fluid velocity, temperature, skin friction coefficient and Nusselt number are discussed in tables and figures. In comparison of all shapes, this study found that blade shaped nanoparticles have the highest values of skin friction coefficient and Nusselt number. The parameters blobid0.pngblobid1.pngblobid2.png and blobid3.png decrease the velocity profiles but increase the temperature profiles.

Semi-numerical Scheme for Mixed Convection Flow of Hybrid Nanofluids with Viscous Dissipation and Dynamic Viscosity

Semi-numerical Scheme for Mixed Convection Flow of Hybrid Nanofluids with Viscous Dissipation and Dynamic Viscosity

Role of internal heat generation, magnetism and Joule heating on entropy generation and mixed convective flow in a square domain

This study has computationally inspected the role of internal heat generation, magnetism, and Joule heating on mixed convective flow and entropy generation in an air-filled square domain. The right cold wall of the differentially heated domain is sliding in its plane at a fixed speed, giving rise to two distinct flow configurations: aiding and opposing flows based on the direction of the sliding wall. In addition, a uniform magnetic field is applied horizontally parallel to the domain with the facility of Joule heating and volumetric heat generation. The fluid flow and the heat transfer within the square domain are formulated by continuity, momentum, and heat energy conservation equations, which are solved using the Galerkin finite element method after imposing appropriate boundary conditions. Numerical simulations are carried out under five distinct cases over a specific range of Reynolds number (31.623 ≤ Re ≤ 316.23), Grashof number (103 ≤ Gr ≤ 105), Richardson number (0.1 ≤ Ri ≤ 10) for mixed convective laminar flow consideration, Hartmann number (0 ≤ Ha ≤ 17.783), and Stuart number (0 ≤ N ≤ 3.162) for the variation of the strength of the uniform magnetic field under Joule heating, and volumetric heat generation coefficient (0 ≤ Δ ≤ 2) for internal thermal generation. The detailed quantitative results incorporate both the thermal and mechanical performances of the system, leading to several important conclusions outlined in their respective cases. It is found that increasing both Re and Ha or increasing Re and decreasing N with fixed Gr lead to higher heat transfer and reduction of the average fluid temperature inside the domain with less experienced drag and higher total entropy generation. Meanwhile, pure mixed convection exhibits higher heat transfer with increasing Gr, particularly when no internal heat is generated.

Mixed Convection Flow of Hybrid Nanofluids with Viscous Dissipation and Dynamic Viscosity

Mixed Convection Flow of Hybrid Nanofluids with Viscous Dissipation and Dynamic Viscosity