Skin Friction Research Articles

Tangent hyperbolic nanofluid flow through a vertical cone: Unraveling thermal conductivity and Darcy–Forchheimer effects

Purpose: This paper demonstrates the way tangent hyperbolic nanofluid flow through a vertical cone is influenced by varying viscosity and varying thermal conductivity. This study also seeks to illustrate the impact of convective boundary conditions on a fluid. The mathematical modeling also takes the Darcy–Forchheimer effect into account. Methodology: Using the appropriate similarity transformation, the fluid problem is reduced into a set of nonlinear ordinary differential equations. These systems of differential equations are evaluated numerically by applying the Optimal Homotopy Asymptotic Method. Findings: The nature of emergent parameters is examined in relation to the temperature distribution, nanoparticle concentration profile, and velocity profile. An increase in variable viscosity corresponds to a decrease in fluid velocity, while enhanced thermal conductivity results in elevated fluid temperature. The skin friction coefficient, Sherwood, and Nusselt numbers are numerically examined for active concerned parameters. These findings can be put into practice in a variety of fields such as polymer cooling systems and medication. Originality: Existing literature has yet to explore the combination of tangent hyperbolic nanofluids with varying viscosity and thermal conductivity under convective boundary conditions.

Unsteady MHD flow analysis of hybrid nanofluid over a shrinking surface with porous media and heat generation: Computational study on entropy generation and Bejan number

The use of hybrid nanofluids in real-world situations is essential for enhancing the efficiency of heat transmission, especially in cooling semiconductor technology and industrial processes. The entropy generation on unsteady Al2O3-Cu/H2O hybrid nanofluid flow over a three-dimensional shrinking sheet is addressed numerically in this study, taking into account the effects of magnetohydrodynamic (MHD), nonlinear thermal radiation, porous media, heat generation, viscous dissipation, joule heating, and convective conditions. Using well-known non-similarity transformations, the model is carefully converted from partial differential equations (PDEs) to ordinary differential equations (ODEs). Afterwards, the behaviors of critical physical characteristics are uncovered across different parameter configurations by a numerical solution using the finite difference technique in bvp4c MATLAB. The velocity profiles of hybrid nanofluid grow proportionately with increases in the values of ϕ2,M,A,K and λ parameters. As Rd,θw,Ec,Bi,H and ϕ2 increase, the temperature of the hybrid nanofluid rises, but as M and A increase, the temperature falls. The local skin friction in both the x and y- directions is increased by enhancing the unsteadiness A, nanoparticle volume fraction ϕ2, magnetic M, porous media K, and the ratio of strain rate λ parameter on the shrinking surface. The local Nusselt number is improved by cumulative the unsteadiness A, nanoparticle volume fraction ϕ2, magnetic M, and Biot number Bi parameter in the direction of a shrinking surface, while the Nusselt number decreases when Eckert number Ec, thermal radiation Rd, heat production H, and temperature ratio θw are improved. An upsurge in the magnetic parameter leads to the development of entropy generation. Increasing levels of the magnetic parameters led to a reduction in the Bejan number. At a nanoparticle volume fraction of 1 % and a nonlinearity radiation scenario, where the unsteadiness values are 0.5, the Nusselt number for hybrid nanofluid shows an estimated improvement of 10.55 % compared to regular nanofluid.

Bejan number and entropy generation analysis of unsteady MHD non-Newtonian micropolar squeezed trihybrid nanofluid flow

Microscopic particles have incredible thermal conductivity making them essential in nanotechnology, electronics, materials science and heat exchangers. For suitable optimization of thermic engineering structure, thermal transportation has to increased but minimized the entropy generation. One of the basic reasons for the developing interest in tri hybrid nanofluids is its unique ability to increase thermal characteristics, that is very useful in numerous heat exchangers. Three distinct nanosized particles, namely silver, gold and diamond are considered with water as a base liquid. A set of dimensionless ODE’s are solved numerically by Bvp4c technique. The results of prominent parameters are elaborated and graphs are presented for velocity profile, entropy profile, Bejan and temperature profiles. Moreover, present result is compared with the literature and found a good agreement. It is observed that the Bejan number and entropy generation shows the opposite behavior for higher values of Casson and magnetic parameter. Further, it is noted that at the lower disk, squeezed Reynold number increases the skin friction coefficient and opposite trend noted against the upper disk. Temperature profile shows increasing trend for higher values of Eckert number. It is also noted that both velocities, temperature, entropy and Bejan number profiles for tri-hybrid nanofluid flow attains maximum values as compared to bi-hybrid and mono nanoparticles.

3D Numerical Modeling of Negative Skin Friction Effects on Tapered Piles in Soft Soils

3D Numerical Modeling of Negative Skin Friction Effects on Tapered Piles in Soft Soils

Combustion performance of hydrogen fueled parallel wall-jet used for drag reduction in a supersonic combustor

Hydrogen fueled parallel wall-jet combustion is considered to be one of the most promising drag reduction technologies in supersonic combustors, researchers mainly focus on its drag reduction mechanism, while balancing its combustion efficiency and drag reduction performance is of great significance for engine performance and energy conservation. In this paper, combustion performance of hydrogen fueled parallel wall-jet is numerically investigated. Kinetic reaction rate and scalar dissipation rate are defined to decouple the chemical reaction and mixing processes. Results indicate that although hydrogen fueled parallel wall-jet combustion is a nonequilibrium chemical reaction process, the combustion process is dominated by mixing due to the much larger magnitude order of kinetic reaction rate. The investigation also reveals that, compared to the effects of mainstream total temperature, mainstream Mach number presents a more significant effect on combustion efficiency. Moreover, combustion efficiency increase first brings negative and then brings beneficial effects on drag reduction performance, which is due to the different sensibilities of the two skin friction determinants viscosity and velocity gradient to combustion efficiency. It is found that, viscosity is more sensitive to combustion efficiency, with combustion efficiency increases by 5.4 %, viscosity increases by 4.15 %, while velocity gradient only decreases by 2.19 %.

Numerical analysis of non-linear radiative Casson fluids containing CNTs having length and radius over permeable moving plate

Abstract Casson fluids containing carbon nanotubes of various lengths and radii on a moving permeable plate reduce friction and improve equipment efficiency. They improve plate flow dynamics to improve heat transfer, particularly in electronic cooling and heat exchangers. The core objective of this study is to investigate the heat transmission mechanism and identify the prerequisites for achieving high cooling speeds within a two-dimensional, stable, axisymmetric boundary layer. This study considers a sodium alginate-based nanofluid containing single/multi-wall carbon nanotubes (SWCNTs/MWCNTs) and Casson nanofluid flow on a permeable moving plate with varying length, radius, and nonlinear thermal radiation effects. The plate has the capacity to move either parallel to or perpendicular to the free stream. The governing partial differential equations for the boundary layer, which are interconnected, are transformed into standard differential equations. These equations are then numerically solved using the Runge–Kutta fourth-order scheme incorporated in the shooting method. This research analyses and graphically displays the effects of factors including mass suction, nanoparticle volume fraction, Casson parameter, thermal radiation, and temperature ratio. Additionally, a comparison is made between the present result and the previous finding, which presented in a tabular format. The coefficient of skin friction decreases in correlation with an increase in Casson fluid parameters and Prandtl number. Heat transfer rate decreases with a variation in viscosity parameter, while it is increasing with an increase in Prandtl number. In addition, this study demonstrates that heat transfer rate for MWCNT is significantly higher than that of SWCNT nanoparticles. Thermal radiation and temperature ratio reduce the heat transfer rate, whereas nanoparticle volume fraction and Casson parameter enhance it over a shrinking surface.

Fractional Analysis of Magnetohydrodynamics Maxwell Flow Over an Inclined Plate with the Effect of Thermal Radiation

This current study provides a comprehensive examination of a novel method for studying the dynamics of a fractionalized Maxwell flow near an inclined plate, considering non-uniform mass transfer through a permeable media. Through the use of partial differential equations, incorporating heat and mass movement effects, the study employs a combination of generalized Fick’s and Fourier’s law with the Caputo operator. Transforming the fractionalized model into dimensionless form using appropriate dimensionless values, semi-analytical solutions for the non-dimensional transmitted fractional model are obtained via the Laplace transformation method. Through graphical analysis, the precise contributions of key parameters such as heat generation, radiation, and chemical reactions are elucidated, including their impacts on the calculated heat generation parameter (Qo), radiation parameter (Nr), and others. The study’s significance lies in its implications for the design of efficient heat exchangers, fluid flow systems, and cooling components in complex engineering systems, including nuclear reactors and power generation plants. Furthermore, the fractional derivative approach offers a more accurate representation of the viscoelastic behavior of materials like polymers, crucial for optimizing fabrication processes such as extrusion and molding. The insights gained from this study extend to the realm of miniaturized fluidic devices, including bio-analysis tools, lab-on-a-chip technology, and microfluidic drug delivery systems, where improved performance and control need a grasp of Maxwell fluid dynamics. The physical outcome of this research lays the groundwork for future investigations that will maximize heat transfer efficiency in real-world systems and give insightful information on the behavior of complicated fluids. We compute and display the skin friction, mass and heat transfer rate in tabular form.

Consequences of Thermal Diffusion and Chemical Reaction on Mixed Convection MHD Casson Fluid through Porous Media with Inclined Plates

In this present article, we analyzed the effects of Thermal diffusion and chemical reaction on nonlinear mixed convection MHD flow of viscous, incompressible and electrically conducting fluid past an inclined porous channel under the influence of thermal radiation and chemical reaction. The transformed conservation equations are solved analytically subject to physically appropriate boundary conditions by using two term perturbation technique. The numerical values of fluid velocity, fluid temperature and species concentration are displayed graphically whereas those of skin friction coefficient, rate of heat transfer and rate of mass transfer at the plate are presented in tabular form for various values of pertinent flow parameters. It is observed that the velocity is decreased with increasing magnetic field parameter. The resultant velocity and concentration has enhances with increasing thermal diffusion parameters. The study is relevant to chemical materials processing applications.

The Soret-Dufour Effects on Three-Dimensional Magnetohydrodynamics Newtonian Fluid Flow over an Inclined Plane

The three-dimensional (3D) model of the fluid flow model with length, breadth, and height or depth is the advanced and precise version from the two-dimensional (2D) model which just lies on a flat surface. The heat transfer in the boundary layer flow have numerous applications in the production of polymer, plastic films, and paper production. Therefore, this paper solves 3D magnetohydrodynamics Newtonian fluid flow model with the effect of Soret-Dufour parameters. Compared with the previous report where the 3D model is without the inclination angle (all the axes are located at their fixed position), this paper considers the boundary xy-plane being projected by a certain angle from the z-axis. The initial partial differential equations (PDEs) are subsequently reduced to ordinary differential equations (ODEs). The MATLAB bvp4c program is chosen to solve the ODEs and the results velocity profile, temperature profile, concentration profile, skin friction coefficient, local Nusselt number, and local Sherwood number. It can be inferred that the magnetic parameter is responsible to the decrement of the velocity profile and skin frictions coefficient. The enhancement of the temperature and the local Sherwood number are caused by the Dufour number. Besides, concentration and the local Nusselt number are enhancing due to the increasing Soret number.

The evaluation of error estimation for the Casson hybrid nanofluid flow in the uniform gap between two tubes for drug delivery applications

ABSTRACT Hybrid nanofluids are capable of being used as a carrier for delivering drugs to targeted areas in the body. For this purpose, the Casson hybrid nanofluids (HNFs) flow is suggested between the gap of two tubes. The study involves analyzing blood-based hybrid nanofluids (HNFs) that consist of silver (Ag) and titanium dioxide (TiO2) nanoparticles for applications of drug delivery. Titanium oxide nanoparticles, or TiO2 NPs, have strong photoactivity, low toxicity, and excellent biocompatibility, making them promising candidates for cancer treatment. The attractiveness of silver nanoparticles (AgNPs) for cancer therapy is due to their unique properties. Graphic representations are provided based on the simulations of non-dimensional velocity, temperature, and skin friction under physical parameter variations, for the applications of drug delivery are investigated and discussed. The control volume finite element method (CVFEM), is used to solve the problem. The new strategy of artificial neural networks (ANN) is also used to solve the transform equations. Nanoparticles increase drug stability and extend shelf life by protecting them from degradation or inactivation.

Similar Solutions for Changing Characteristics of Natural Convection Laminar Flow around a Vertical Rectangular Inclined Plane Surface

The study investigates laminar natural convection flow around a vertical rectangular inclined plane surface, specifically focusing on the effects of viscous and pressure stress work. Previous research primarily addressed these effects in two-dimensional natural convection flow scenarios, while this study extends the analysis to encompass three exterior situations, accounting for variations in fluid properties outside compressible boundary layers. Employing numerical methods, the study aims to predict essential flow parameters including Prandtl’s number (Pr), controlling parameter (C), and additional parameters (A, B, D, E, ∅). The investigation yields velocity profiles (F'(0), S'(0)), temperature profiles , skin frictions (F''(0), S''(0)), and heat transfer coefficients θ'(0). Numerical results are presented to illustrate the impact of different parameters on these flow characteristics. Additionally, tabulated data in Tables-2 and Tables-3 offer further insights into the predicted flow parameters and their variations under varying conditions.

Numerical analysis of the MHD Williamson nanofluid flow over a nonlinear stretching sheet through a Darcy porous medium: Modeling and simulation

Abstract In the current study, we delve into examining the movement of a nanofluid within a Williamson boundary layer, focusing on the analysis of heat and mass transfer (HMT) processes. This particular flow occurs over a sheet that undergoes nonlinear stretching. A significant facet of this investigation involves the incorporation of both the magnetic field and the influence of viscous dissipation within the model. The sheet is situated within a porous medium, and this medium conforms to the Darcy model. Since more precise outcomes are still required, the model assumes that both fluid conductivity and viscosity change with temperature. In this research, we encounter a system of extremely nonlinear ordinary differential equations that are treated through a numerical technique, specifically by employing the spectral collocation method. Graphical representations are used to illustrate how the relevant parameters impact the nanoparticle volume fraction, velocity, and temperature profiles. The study involves the computation and analysis of the effect of physical parameters on the local Sherwood number, skin friction coefficient, and local Nusselt number. Specific significant findings emerging from the present study highlight that the rate of mass transfer is particularly influenced by the thermophoresis factor, porous parameter, and Williamson parameter, showing heightened effects, while conversely, the Brownian motion parameter demonstrates an opposing pattern. The results were computed and subjected to a comparison with earlier research, indicating a notable degree of conformity and accord.

Mixed Convection Flow of a Casson Fluid Past a Thin Needle

Mixed Convection Flow of a Casson Fluid Past a Thin Needle

Unsteady Flow of Hybrid Nanofluids Subjected to a Stretching/Shrinking Sheet with Heat Generation

Unsteady Flow of Hybrid Nanofluids Subjected to a Stretching/Shrinking Sheet with Heat Generation

Nonlinear dynamics of dissipative water conveying SWCNT/MWCNT/Ferro nanofluid subject to radiation: Thermal analysis by linear slope regression

Carbon nanotubes have gained significant attention due to their unique properties like small dimensions, high thermal conductivity, and unique architecture. These nanotubes have enormous potential in various fields such as nanomedicine, mechanical compound materials, sensor devices, bio-sensors, and many other applications. The present study investigates the impact of adding nanoparticles such as iron oxide (Fe3O4), single-walled carbon nanotubes (SWCNT), and multi-walled carbon nanotubes (MWCNT) on magnetohydrodynamics (MHD) oscillatory water-based flow over a porous medium. The aim is to examine the effect of heat and mass transfer rate and radiative viscous dissipation that interacts with Fe3O4 nanoparticles and carbon nanotubes. The governing equations of the dynamic nanofluid systems are transformed into a set of coupled nonlinear partial differential equations through suitable dimensionless transformations and further converted into ordinary differential equations by taking appropriate solutions for oscillatory-type nanofluid flow. The homotopy perturbation method is applied to solve the governing equations with oscillatory boundary conditions and the solution is also compared with the numerical solver bvp4c. The rate of increase in the temperature and Heat Transfer are computed by the linear slope regression method and results are computed for nanoparticles SWCNT, MWCNT, and Ferro. Also, Skin friction and rate of heat transfer are computed and compared for the nanoparticles with varying Peclet and Eckert numbers. The velocity profile and temperature profile of SWCNT/MWCNT/Ferro nanofluids are being compared. The heat transfer rate is observed to be high for Ferro nanoparticles compared to SWCNT and MWCNT.

Flow analysis of MHD ternary hybrid nanofluid over a permeable wedge with variable surface temperature and slip effect

A comparative flow analysis of a water based- ternary hybrid nanofluid has been studied in this article over a moving permeable wedge in the presence of variable wedge surface temperature. The model has been developed keeping in mind magnetic, velocity slip, buoyancy, and suction effects. The primary nanoparticle was Nimonic 80A, Fe 3 O 4 being the secondary nanoparticle and Graphene Oxide ( GO ) ternary nanoparticle. The velocity, temperature, heat transfer rate, and shear drag profiles for various parametric values of the magnetic parameter ( M ), velocity ratio parameter ( R ) , velocity slip parameter ( h ) , buoyancy parameter ( γ ) and suction parameter ( S ) was investigated. MATLAB bvp4c code was utilized for obtaining the numerical results by solving the nondimensional differential equations obtained using similarity transformations. All the results and graphs were formulated after a positive outcome of our results with that available in existing literature. An increase in the velocity slip parameter ( h ) and velocity ratio parameter ( R ) resulted in an increase in velocity profiles and local Nusselt number graphs while a reverse trend was observed for temperature and skin friction profiles. Also, the velocity graphs faced an increase by 0.09% with an increment in M = 0.4 to M = 0.8 . The present study finds its extensive applications in medical industries, water heaters, and forging of hot exhaust valve heads.

Legendre wavelet integration operational matrix method for the numerical solution of unsteady MHD nanofluid flow between moving parallel plates

This study proposes a novel method based on Legendre wavelet integration operational matrix for solving a system of nonlinear ODE’s to model the two-phase, unsteady nanofluid flow and heat transfer between parallel plates in presence of magnetic field. To validate the applicability of proposed method, system of nonlinear BVP with exact solutions is employed as a test problem. Test problem results are compared with exact solution, and other numerical methods. The governing equations were then changed using similarity transformation into a set of nonlinear ODE’s. . Following this, the LWOMM is applied for the proposed problem. Findings demonstrated that, for a constant Reynolds number, skin friction coefficient value increases with rising Hartmann and squeezing numbers. Furthermore, it is demonstrated that Eckert number is a reducing function of the squeeze number and Nusselt number is an increasing function of Hartmann number.

Transient skin friction behavior associated with hemisphere-based vortex ring collisions

Global and local transient skin friction variations resulting from a large-eddy simulation study on ReΓ0=3000 vortex rings colliding with surface-mounted hemispheres of hemisphere-to-vortex-ring diameter-ratios of 0.5≤D/d≤2 are investigated here. Skin friction distribution changes due to the approaching primary vortex ring, formation of secondary/tertiary vortex rings, subsequent mutual interactions between various vortex ring structures, and azimuthal instabilities are clarified with a view to better establish their relationships when the relative hemisphere size varies. Results show that the primary vortex ring produces the highest skin friction levels when it is close to or collides with the hemisphere/flat wall. Additionally, entrainment of wavy secondary/tertiary vortex rings leads to them entangling around the primary vortex ring and resulting in segmented skin friction regions at later stages of the collision process, regardless of the diameter-ratio. Unlike smaller hemispheres, the largest D/d=2 hemisphere here restricts all skin friction changes along its surface with the flat wall unaffected. It is also revealed here that while the diameter-ratio governs the global skin friction distributions, how secondary/tertiary vortex rings interact with the primary vortex ring and how azimuthal instabilities manifest and evolve for all the various vortex rings confer strong influences on the breaking-up and dissipation of regions with high skin friction levels.

Direct numerical simulation of compressible turbulent channel flows over porous boundaries

The impact of porous boundaries on skin friction and heat transfer in compressible turbulent channel flows is explored through direct numerical simulations. Utilizing the volume-averaged Navier–Stokes equations for the porous media, we examine flows at Mach numbers Mb=0.3 and Mb=1.5, with friction Reynolds numbers ranging from 176 to 220, across three permeability levels: 0 (impermeable), 1.6×10−5, and 1.0×10−4. Our findings reveal a dual impact of porous boundaries on skin friction: a direct reduction due to averaged slip velocity at the interface and an indirect increase from amplified Reynolds shear stress due to enhanced wall-normal permeability. This permeability weakens the wall-blocking effect, leading to intensified wall-normal velocity fluctuations and consequently higher Reynolds stress. Additionally, the Mach number significantly influences flow structures, particularly at higher permeabilities, where it disrupts near-wall streaks at Mb=0.3 but has a diminished effect at Mb=1.5. Thermal analysis confirms the validity of the generalized Reynolds analogy for the mean temperature in these flows, with the turbulent Prandtl number approximating 1, in line with the strong Reynolds analogy. Moreover, a strong spatial correlation between heat flux and wall shear stress fluctuations underscores the intertwined dynamics of momentum and thermal transport at the porous–fluid interface.

Entropy Analysis of Hall Effect with Variable Viscosity and Slip Conditions on Rotating Hybrid Nanofluid Flow Over Nonlinear Radiative Surface

PurposeWith possible uses in engineering and industrial processes, this work aims to further our knowledge of fluid dynamics and heat transfer in complicated flow configurations. This study looks at how Al2O3−Cu/H2O hybrid nanofluids move across a nonlinear radiative 3D unsteady surface. It tries to figure out what happens when the Hall current, variable viscosity, viscous dissipation, velocity and thermal slip conditions work together. The goal of this analysis is to provide insight into the system's thermodynamic behavior and the ways in which these elements affect the flow's entropy generation. MethodologyThe controlling system is converted into nonlinear nondimensional partial differential equations (PDEs) by applying suitable non-similar transformations. In this work, the governing equations are simulated using the local non-similarity (LNS) approach up to the second truncation level using the numerical technique bvp4c in MATLAB. FindingsThe temperature, velocity, entropy production, skin friction in both directions, and Nusselt number profiles of the nanofluid and hybrid nanofluid are detailed in many figures. The tabular form contains the results of computing the local Nusselt number for linear, nonlinear, and radiation-free scenarios. The velocity profiles in both directions and the temperature profile grow as the rotation parameter and nanoparticle volume fraction parameter increase. Conversely, the velocity profiles drop when the variable viscosity parameter falls, while the temperature profile increases. When the unsteadiness parameter A is set to 0.5 and the nanoparticle volume fraction is 1%, hybrid nanofluid has 4.26% lower x-direction skin friction than nanofluid and 3.62% greater y-direction friction. When the unsteadiness parameter A = 0.5 and the nanoparticle volume percentage is 1%, a hybrid nanofluid has a 2.77% higher Nusselt number than a nanofluid. The generation of entropy was also enhanced by an increase in the volume fraction of nanoparticles, radiation, temperature ratio, and Brinkman number. We evaluate and contrast the results of this study with those of earlier research.