Mixed Convection Flow Research Articles

Influence of oscillatory hydromagnetic field with mixed convection driven Sutterby nanofluid flow over a stretching cylinder

A nonlinear mixed convective sutterby nanofluid flow along a stretching cylinder is being studied in this article. The set of partial differential equations (PDEs) that control fluid flow is nonlinear and subject to surface constraints and similarity transformation reduces a system of PDEs to non-dimensional ordinary differential equations (ODEs), which are then solved in MATLAB Bvp5c solver which is based on the Runge–Kutta method and Shooting technique. We provide a graphic evaluation of the significant contributions made by the various physical terms to engineering measurements in the curiosity and transport domains. The study discovers that temperature distribution increases heat border viscosity but reduces thermal diffusion, whereas nonlinear convection heat improves surface heat transfer. The periodic magnetic field raises the fluid temperature while decreasing the rate of energy transfer. Furthermore, experiments have demonstrated that oscillating magnetic fields induce fluctuations with a sinusoidal pattern. Furthermore, the current study has applications in the design and manufacture of cylinder-shaped objects in various fields such as aerospace engineering, geophysics, and nuclear engineering. These include core catchers in nuclear power plant steam turbines, waxy crude oils or foodstuffs in centrifugal pumps, and deformation rates that frequently occur in practical turbomachinery and other industrial processes.

Mixed Convection Flow of MHD Casson Nanofluid over a Vertically Extending Sheet with Effects of Hall, Ion Slip and Nonlinear Thermal Radiation

This manuscript investigates the effects of viscous dissipation, Ohmic heating, nonlinear thermal radiation, chemical reactions, Hall current, and ion slip on the mixed convection flow of magnetohydrodynamic (MHD) Casson nanofluid over a vertically stretching sheet in a spongy medium. The strongly nonlinear ordinary differential equations (ODEs) derived from the governing equations are solved using a sixth-order, seven-stage Runge–Kutta (RK6) method in conjunction with the shooting technique. Numerical simulations are conducted using an open-source Python programming language. The study evaluates temperature, velocity, nanoparticle concentration, skin friction coefficients, Nusselt number (rate of heat transfer), and Sherwood number (rate of mass transfer) based on dimensionless parameters. Key findings reveal that increasing ion slip and Hall currents enhance the velocity profile in the x-direction, while the Casson parameter exerts a diminishing effect. The fluid temperature decreases with higher Hall current, Casson parameter, and ion slip values but increases due to nonlinear thermal radiation, the temperature ratio parameter, and the Eckert number. Furthermore, the chemical reaction parameter and Schmidt number reduce nanoparticle concentration within the boundary layer, with the Casson parameter amplifying this effect. The study also examines the rates of mass, heat, and momentum transfer near the surface under varying parameter influences, presenting results through comprehensive graphs and tables. To validate the numerical method, a comparative analysis is conducted against previous studies, demonstrating excellent agreement and thus confirming the reliability and accuracy of the computational approach.

Mixed convective flow analysis of a Maxwell fluid with double diffusion theory on a vertically exponentially stretching surface

It observers that an object is submerged in a liquid, more pressure is applied to its bottom surface than its top surface, as a result pressure rises within depth of fluids. A buoyancy force is generated due to the pressure difference. In the current investigation, the mathematical formulation of bio-convective stagnation point flow of a radiative Maxwell fluid with multiple slip effect on an exponentially porous stretching surface is analyzed thoroughly. The buoyancy assisting and opposing conditions with magnetic field are discussed in the current investigation. Moreover, the energy and concertation equations are formulated by the utilization of Cattaneo–Christov theory and non-uniform heat source/sink. The flow model is developed in the form of partial derivatives, then use the similarity variables to convert the physical system into nonlinear ordinary derivative. The nonlinear system is tackled numerically with the help of Bvp4c approach on the MATLAB. The graphical upshots for various emerging parameter are observed with two aspects: buoyancy assisting λ>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {\\lambda > 0} \\right)$$\\end{document} and buoyancy opposing λ<0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {\\lambda < 0} \\right)$$\\end{document}. The observation shows that the greater values of mixed convection parameter improves the fluid velocity for assisting flow λ>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {\\lambda > 0} \\right)$$\\end{document}, while declining trend is noticing for opposing flow situation λ>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {\\lambda > 0} \\right)$$\\end{document}. Further, it is worth noticing that stronger inputs of thermal and concentration relaxation parameter yield lesser thermal and concentration diffusivity, which reduces the temperature and nanoparticles concentration.

Multiple shape factor effects of nanofluids on marangoni mixed convection flow through porous medium

This study explores the effects of multiple shape factors on nanofluids within Marangoni mixed convection flows through porous media. Nanofluids, containing nanoparticles in a base fluid, show unique thermal properties, making them valuable in cooling systems, energy storage, and medical devices. Marangoni mixed convection, driven by surface tension gradients, adds complexity to fluid dynamics and heat transfer in porous media. Analytical and numerical analyses examine how various particle geometries, nanoparticle volume fractions, and porous medium configurations influence transport phenomena. Entropy analysis calculates thermodynamic irreversibilities. Findings reveal relationships between shape factors, heat transfer rates, velocity profiles, temperature distribution, and entropy generation rates, offering insights for optimizing nanofluid-based systems. The study also investigates magnetic forces, heat source/sink effects, and viscous dissipation on thermal energy transfer in Graphene oxide/water and Molybdenum disulfide/water nanofluids. Using similarity transformations, Partial Differential Equations are converted into Ordinary Differential Equations, solved with HAM and NDSolver by using the Wolfram tools. Results graphically depict velocity, temperature, entropy, and skin friction values, providing practical insights for engineering applications.

Non-Similar Analysis of Mixed Convection Biomagnetic Boundary Layer Flow Over a Vertical Plate with Magnetization and Localized Heating/Cooling

Theoretical and numerical investigation of an applied magnetic field on mixed convection flow of a biofluid through a vertical plate using contained heating or cooling is observed in this study. The mathematical formulation is that of the full Biomagnetic Fluid Dynamics (BFD) model which deals with on the ferrohydrodynamics (FHD) and magnetohydrodynamics (MHD) principle. In this work, the study is performed on a specific biofluid, viz. human blood. Assume that the magnetization very linearly with magnetic field strength, temperature dependency of dynamic viscosity and thermal conductivity is noticed. A system of non-linear equations with appropriate boundary condition is obtained by familiarizing suitable non-dimensional variables in the physical problem. For the numerical solution, we used finite difference method which is based on an efficient technique is applied in the problem. Computations for flow profiles, local skin friction coefficient and local heat transfer coefficient are performed with the magnetic parameter Mn, the viscosity/temperature parameter θr and the thermal/conductivity parameter S∗. The effect of the localized heating or cooling is examined. The computational results presented graphically and have been validated in an appropriate manner. The study reveals that the impact of a magnetic field for blood flow in arteries is found significantly. The results presented bear the promise of valuable applications in physiology, medicine and bioengineering.

Fractional numerical analysis of γ-Al2O3 nanofluid flows with effective Prandtl number for enhanced heat transfer

Abstract Nanoparticles have gained recognition for significantly improving convective heat transfer efficiency near boundary layer flows. The characteristics of both momentum and thermal boundary layers are significantly influenced by the Prandtl number, which holds a crucial role. In this vein, the current study conducted a detailed computational analysis of the mixed convection flow of $\gamma$Al$_2$O$_3$-H$_2$O and $\gamma$Al$_2$O$_3$-C$_2$H$_6$O$_2$ nanofluids over a stretching surface. This research integrates an effective Prandtl number, utilizing viscosity and thermal conductivity models based on empirical findings. Additionally, a unique double-fractional constitutive model is debuted to accurately evaluate the effective Prandtl number’s function in the boundary layer. The equations were solved using a numerical technique that combined the finite-difference method with the L$_1$ algorithm. This investigation presents numerical findings related to the velocity, temperature distributions, wall shear stress coefficient, and heat transfer coefficient, contrasting scenarios with and without the effective Prandtl number. The research shows that integrating nanoparticles into the base fluids reduces the temperature of the nanofluid with an effective Prandtl number while enhancing the heat transfer rate irrespective of its presence. Nonetheless, the introduction of a fractional parameter reduced the heat transfer efficiency within the system. Notably, the $\gamma$Al$_2$O$_3$-C$_2$H$_6$O$_2$ nanofluid demonstrates superior heat transfer enhancement capabilities compared to its $\gamma$Al$_2$O$_3$-H$_2$O counterpart but also exacerbates the drag coefficient more significantly. Many practical applications of this study include electronics cooling, industrial process heat exchangers, and rotating and stationary gas turbines in power plants, and efficient heat exchangers in aircraft.

Unsteady wake and heat transfer characteristics of three tandem circular cylinders in forced and mixed convection flows

In natural convection (high Richardson number Ri), a high Prandtl number (Pr) leads to thinner thermal boundary layers, enlarging the thermal gradient and hence the enhancement of buoyancy effect. In forced convection (low Ri), a high Pr introduces thicker velocity boundary layers. In mixed convection scenarios, where both forced and natural convection are significant, the interaction between Pr and Ri determines the resultant flow pattern and heat transfer characteristic. Three tandem circular cylinders with an identical spacing ratio of 4.0 in both forced and mixed convection flows were numerically investigated by using finite element method. The computations were carried out in the range of Pr = 5–50 and Ri = 0–2 at a low Reynolds number of Re = 150. The results of the squared strain rate and the vorticity shed light on the enstrophy transfer process. Thermal plume structures in the far wake originate from the upper dispersed vortices due to the high superimposed buoyancy at low Pr, while they are suppressed at high Pr. The increase in Pr plays a role as the flow stabilization, while the growth of Ri plays the reverse role. The time-averaged velocity, pressure coefficient, and temperature become more asymmetrical at high Ri. The Nusselt number of the upstream cylinder is approximately equal to the empirical result without the consideration of thermal buoyancy. Due to the thermal buoyancy, the migration of shear layers along the cylinder surface leads to the frequency alteration and harmonic frequency in the drag, lift, and Nusselt coefficients.

Investigation of the characteristics of optically dense gray mixed convection fluid flow along a cantilever shape

The goal of the work under consideration is to inspect the steady buoyancy driven flow for a viscous and density independent fluid along a cantilever shape, by considering the optically dense gray fluid. This study examines the characteristics of buoyancy driven convective heat and fluid flow adjacent to the cantilever shape. The governing equations constituting the aforementioned problem are converted into ordinary differential equations by utilizing the stream function formulation. The shooting technique BVP4C along with the MATLAB program is then used to obtain the numerical solutions. The impact of dimensionless cantilever shape parameter n, Prandtl number Pr, Richardson parameter λ, and thermal radiation parameter F on the velocity and temperature profile of the cantilever shape is demonstrated graphically. The tables provide the results for the skin friction and rate of heat transfer coefficient due to the impact of a number of evolving parameters.

Magnetohydrodynamic convection in a heat-generating ferrofluid within a corrugated cavity containing a rotating cylinder

This study introduces a novel approach by combining magnetohydrodynamic flow with Joule heating effects to investigate the conjugate mixed convective flow of ferrofluid in a non-homogenously warmed wavy-walled squared-shaped chamber with a spinning cylindrical object positioned at the center of the chamber. The current study seeks to maximize heat transmission effectiveness by scrutinizing optimum system attributes and conducting entropy production analysis. Numerical solutions are achieved by employing the Galerkin finite element weighted residual approach to solve the two-dimensional Navier–Stokes and heat energy equations representing the mathematical model. The parametric alterations encompass Grashof (103 ≤ Gr ≤ 106), Reynolds (31.62 ≤ Re ≤ 1000), and Hartmann (5.623 ≤ Ha ≤ 31.623) numbers, volumetric heat generation coefficient (0 ≤ Δ ≤ 10), thermal conductivity ratio (K = 20.07, 95.14), corrugation frequency (6.5 ≤ f ≤ 8.5), dimensionless corrugation amplitude (0.02 ≤ A ≤ 0.04), and dimensionless cylinder diameter (0.3 ≤ D ≤ 0.5). The study assesses the thermal characteristics of a heat source and the entropy generated within the computational domain while considering varying corrugation frequency and amplitude, cylinder diameter, thermal conductivity, strength of magnetism, and heat generation. The findings are quantitatively showcased through the Nusselt number of the hot wall, mean fluid temperature, overall entropy production, and thermal performance criterion (TPC) across the domain. After extensive analysis, it is evident that minimum cylinder diameter (= 0.3), corrugation frequency (= 6.5), and amplitude (= 0.02) while the maximum thermal conductivity ratio (= 95.14) ensure optimal system performance. Surprisingly, incorporating interior heat production diminishes thermal performance significantly while increasing TPC. Understanding the impacts of the magnetic field, Joule heating, and interior heat production on convective flow offers key perceptions into temperature variation, heat transport, velocity profile, and irreversible energy loss in numerous engineering applications.

Impact of free-stream orientation and thermal buoyancy on aerodynamic and heat transfer characteristics in mixed convective flow past an elliptical cylinder

Impact of free-stream orientation and thermal buoyancy on aerodynamic and heat transfer characteristics in mixed convective flow past an elliptical cylinder

Mixed Convection Boundary Layer Flow over a Solid Sphere in AL203-Ag/Water Hybrid Nanofluid with Viscous Dissipation Effects

The current study aims to investigate how heat transfer and skin friction develop by modifications in the fundamental advantages of fluids in the presence of mixed convection boundary layer flow over on a sphere in hybrid nanofluids. The numerical solutions for the reduced Nusselt number, local skin friction coefficient temperature profile, and velocity profiles are discovered and clearly presented. The Eckert number, the mixed convection parameter λ, and the nanoparticle volume fraction are all investigated and described. It is found that increasing the volume percentage of nanomaterial in nanofluid enhanced the value of the skin friction coefficient. The low density of nano oxides in hybrid nanofluids, such as alumina, also contributes to reduced friction between fluid and body surface. The findings of a computational investigation demonstrate that the use of a hybrid nanofluid, composed of nanometal and nano-oxide in the form of , has the potential to decrease skin friction while maintaining heat transfer characteristics comparable to that of Ag/water nanofluid. The findings in this publication are new and will be useful to boundary layer flow researchers. It can also be applied as a guideline for experimental investigations with the goal of reducing the cost of operation

Effects of Al2O3‐Cu‐H2O hybrid nanofluid with Soret and Dufour on mixed convection flow over a curved surface

Effects of Al₂O₃‐Cu‐H₂O hybrid nanofluid with Soret and Dufour on mixed convection flow over a curved surface

Mixed convection heat transfer characteristics of nanofluid under magnetic field based on discrete unified gas kinetics scheme

In this paper, we proposed a discrete unified gas kinetic scheme (DUGKS) into the mixed convection issue coupled in a magnetic field and verified the accuracy by comparing with a exist literature. The flow and heat transfer characteristics of Fe3O4-water nanofluid in the mixed convection are investigated using the DUGKS model. The investigation explores the influence of Hartmann number (0.01 ≤ Ha ≤ 100), Rayleigh number (2 × 103 ≤ Ra ≤ 6 × 105), Richardson number (0.5 ≤ Ri ≤ 10), and nanoparticle fraction (0.01≤ϕ ≤ 0.05) on mixed convection heat transfer and flow characteristics. The results reveal that the critical point for the influence of the Hartmann number on the average Nusselt number is 1. When Ha < 1, the variation of Ha has little effect on Nu, but when Ha > 1, the influence of Ha becomes significant. When Ri = 1, the heat convection between the cold wall and the hot wall is strongest, and the Nusselt number at the cold wall reaches its maximum. The changes in velocity and temperature fields under all conditions are effectively captured by the DUGKS method. Therefore, the proposed method exhibits good mesh adaptability and accurately simulates the mixed convection heat transfer problem.

Radiative double-diffusive mixed convection flow in a non-Newtonian hybrid nanofluid over a vertical deformable sheet with thermophoretic particle deposition effects

Radiative double-diffusive mixed convection flow in a non-Newtonian hybrid nanofluid over a vertical deformable sheet with thermophoretic particle deposition effects

Computational study of magnetohydrodynamic mixed convective flow in a nanofluid-filled cavity with diagonally moving lid

This study examines the phenomenon of uniform magnetohydrodynamic mixed convective flow in a cavity filled with nanofluid. The research focuses on analyzing the mixed convection induced by a uniformly heated lid-driven cavity with diagonal motion. The fluid and heat transport equations are solved using the finite volume method. Numerical simulations are conducted for various parameters including Richardson number (Ri) ranging as 0.1, 1 & 10, Hartmann number (Ha) 0, 10, 25 & 50, angle of inclination (γ) 0°, 30°, 45°, 60° & 90°, and solid volume fraction from 0.0 to 0.05. The results are presented in terms of flow and thermal fields. It is observed that higher Hartmann numbers and inclination angles of the magnetic field lead to a suppression of convection, favoring a dominant conduction mode and reducing the overall heat transfer rate. Specifically, the study highlights a significant enhancement in the heat transfer rate in a nanofluid-filled cavity with a diagonally moving wall. The movement’s of diagonal wall has significant power consumption, the tool may be used in an industrial process that improves heat transfer, offers flexibility, and raises the quality of the finished product. Additionally, the correlations that were found are a useful tool for heat exchanger design.

Electrokinetically controlled mixed convective heat flow in a slit microchannel

AbstractThis study performs a time‐dependent analysis of mixed convection of an incompressible fluid and heat sink/source factor in an upstanding slit superhydrophobic (SHO) microchannel in the involvement of temperature jump and electroosmotic flow conditions. The internal wall of one of the sides in the microchannel is intentionally modified to demonstrate SHO slip and temperature jump conditions. A transverse magnetic effect is introduced in the path of the flow. The steady‐state solutions of the modeled problem have been analytically derived for temperature, velocity, pressure gradient, sheer stress, and heat transfer rate. The derived results are expounded thoroughly with the use of several plots. It is deduced that the elevating mixed convection (Gre), heat source/sink (Qs), Debye–Hückel (K), and nonlinear parameters (N) are observed to increase the fluid flow as time rises, and these effects are all higher when the velocity slip and temperature jump impacts are present. Further, the application of heat‐generating parameters is viewed to encourage the fluid temperature in the microchannel. Finally, the comparison between the current investigation with the previously published findings demonstrates a very good consistency for the limiting cases.

Experimental Investigations of Heat Transfer in Simultaneously Developing Transitional Regime of Mixed Convection Flows in a Vertical Tube

Abstract The study of flow behavior in the simultaneously developing transitional regime of mixed convection flows is rare. It has been believed that the transitional regime will give a good compromise between pressure drop and heat transfer compared to laminar and turbulent flow regime. In this experimental study, the friction factor (f) and Nusselt number (Nu) characteristics for buoyancy-assisted and opposed flows of water in concurrently developing transitional regime of mixed convection through a vertical tube are studied. Experiments were done for Reynolds numbers (Re) varying from 500 to 15,000, Grashof numbers (Gr) from 1.25 × 104 to 5 × 106, Prandtl numbers (Pr) from 3 to 7, and Richardson numbers (Ri) from 0 to 0.1 subjected to uniform heat flux boundary conditions. A flow visualization provision after the test section which confirms an early transition in buoyancy-opposing flow (Rec = 2264) compared to buoyancy-aiding flow (Rec = 2468) at a fixed Ri of 0.1. Further, with the increase in Ri from 0 to 0.1, the average f decreases, and the average Nu increases in both aiding and opposing flows. It confirms that the onset of transition gets delayed with the increase of heat flux supplied in both the flows. Based on the present outcomes, an efficient heat exchanging device can be operated either to delay or advance the transition in a vertical pipe flow for optimum heat transfer.

Mixed convection flow of Magnetohydrodynamic Prandtl nanofluid containing gyrotactic microorganisms: Multi-layer neural network model

Mixed convection flow of Magnetohydrodynamic Prandtl nanofluid containing gyrotactic microorganisms: Multi-layer neural network model

Hybrid carbon nanotubes flow and heat transfer over a vertical thin needle with suction effect: A numerical and optimisation analysis

The present study aims to provide a numerical and optimisation analysis of the hybrid carbon nanotubes flow over a vertical thin needle under the suction effect. The thin needle is suspended in water-based hybrid nanofluids containing a combination of single- and multi-walled carbon nanotubes. The heat is transported using the mixed convection flow. A mathematical model of partial differential equations (PDEs) is developed subject to boundary conditions. The PDEs system is converted to non-dimensional ordinal differential equations (ODEs) by using the similarity solution method. Then, the first order of the ODEs system is solved in a MATLAB bvp4c function. We innovatively carry out an optimisation process using response surface methodology (RSM) to enhance the efficiency of the numerical experiment data and fill a gap in the optimised analysis. To observe the variation solutions for the reduced skin friction and heat transfer coefficients, several parameters, such as the mixed convection and suction parameters, are altered into several values. The solutions are essential for accurately forecasting the occurrence of boundary layer separation, particularly in the case of dual solutions. Our analysis reveals that the model generates multiple solutions for the opposing flow, and the boundary layer separates slowly due to the suction effect. To complete the research, RSM reveals that the highest value of the nanoparticle volume fraction and suction parameters, as well as the smallest value of the needle size, generate the maximum transmitting heat through the slender needle. Furthermore, both the numerical and RSM results show that hybrid carbon nanotubes perform better than mono‑carbon nanotubes for better practical reference.

Stacking regression model approach to mixed convection flow of ternary- nanofluid over slanted surface with magnetic field, waste discharge concentration, and joule heating effects

The current work is carried out to investigate the mixed convection flow behavior of ternary-based nanofluid over an inclined surface in the presence of a magnetic field, waste discharge concentration, and joule heating effects. The governing equations with proper assumptions were converted into ordinary differential equations (ODEs) form by implementing suitable similarity constraints and solved with Runge Kutta Fehlberg 4th 5th order and shooting scheme. The stacking regression model approach is implemented along with the Runge Kutta Fehlberg 4th 5th order technique. The obtained outcomes are presented with graphs, and model correctness is assessed using the combination of Gaussian Process Regression (GPR), Extra Tree Regression (ETR), and Random Forest (RF). The consistency and stability of the model are demonstrated by the closely linked testing and training data. The study outcomes show that the rise in the magnetic constraint will improve the velocity profile while improved values of local pollutant external source and external pollutant source variation parameters will enhance the concentration profile. Enhancement in Eckart number and solid volume fraction values will improve the rate of thermal distribution. Ternary nanofluid shows significant improvement than nanofluid. The surface drag force is increased about 8 %-9 % in assisting flow case and 8 %-17 % for opposing flow case for different values of magnetic parameter, the rate of thermal distribution improved from 75.54 % to 11.55 % in assisting flow case and 16.87 % to 25.70 % in opposing flow case for different values of Eckert number. The study's results might contribute to the advancement of more effective heat exchangers and cooling systems for electronics and engines. Exploration and extraction of oil, as well as the creation of efficient water purification systems.