Velocity Skin Friction Research Articles

Computational influences of convection micropolar fluid influx and permeability on characteristics of heating rate and skin friction over vertical plate

This manuscript merits at examining of an embedded orthogonal plate inside porous domain exposed to uniform heat influx to elaborate on how micro polar fluid factors and permeability characteristic affect the local skin friction, heating rate, and angular velocity inside boundary layer. The plate is subjected to forced convective micro polar fluid influx under steady, incompressible, and viscous circumstances. To facilitate dependable numerical solution, similarity approach is implemented to mutate set of coupled governing equations relevant to the adopted study into a constrained dimensionless differential equations. Computational analysis has been executed hiring Runge-Kutta scheme by Matlab function bvp4c to settle the governing equations. Study's results are highlighted graphically the impact of micro polar fluid factors on the local skin friction, heating rate, and angular velocity curves. High degree of acceptability of present findings compare with prior research results. It is found that the rising of Darcy parameter drives to decrease linearly both heating rate and local skin friction. Among the examined factors, the benchmark parameter of decreasing skin friction is the porosity. Additionally, it is found that an increasing of Prandtl number and micro rotation element lead to enhance Nusselt number. Once curves of micro rotation are interfered at certain distance from the plate due to increase in porosity, Darcy, Forchheimer's, and microelement rotation, the micro rotation curves are inverted.

Thermal and velocity slip conditions together with thermal radiative effects on Joule heating mixed convection MHD hybrid nanofluid flow induced by an exponentially shrinking or stretching sheet

ABSTRACT The present study analyzes the mixed convection with magnetohydrodynamic (MHD) flow, Joule heating, and heat transfer in hybrid nanofluids on exponentially stretching or shrinking sheets. The study aims to optimize heat transfer and fluid dynamics properties in engineering and industrial applications. The governing partial differential equations are converted into ordinary differential equations by employing appropriate similarity transformations and then solved using the BVP4C MATLAB tool. In this study, the effects of silver volume fraction, velocity slip, thermal slip, magnetic field, heat generation, Eckert number, and thermal radiation on the skin friction coefficient, Nusselt number, velocity profile, and temperature profile are examined and graphically discussed. The base fluid water contained 2% silver (Ag) and 0.1% titanium oxide (TiO2) nano-particles in this hybrid model. The dual solution was present for a shrinking sheet ( λ < 0 ) when λ ≥ λ c . The skin friction coefficient values decreased by approximately 37%, while the local Nusselt number increased by approximately 3.1% when the velocity slip increased in the first solution. The Nusselt number increased by approximately 0.28% and 12% when the Eckert number and radiative parameter increased, respectively, but decreased by approximately 7.5% and 0.20% when the thermal slip and heat generation increased, respectively.

Couette flow of viscoelastic dusty fluid through a porous oscillating plate in a rotating frame along with heat transfer

AbstractUsually, suction/blowing is used to control the channel's fluid flow, which is why this worth‐noting effect is considered. The fluid velocity is considered along the x‐axis due to the oscillations of the right plate. The thermal effect on the flow due to the heated right plate is also considered. The fluid and dust particles have complex velocities due to the rotation, which are the sum of primary and secondary velocities. To convert the aforementioned physical phenomenon into mathematical form, partial differential equations are used for modeling the subject flow regime. Appropriate nondimensional variables are employed to nondimensionalize the system of governing equations. With the assistance of assumed periodic solutions, the system of partial differential equations is reduced to a system of ordinary differential equations which is then solved by the perturb solution utilizing Poincare–Lighthill perturbation techniques. The engineering interest quantities, the Nusselt number, and skin friction are also determined. The impact of various parameters on skin friction, viscoelastic fluid, and dust particle velocity profiles is also investigated. It is worth mentioning that suction controls the boundary layer to grow unexpectedly, even in the resonance case. The obtained solution is also valid in the case of injection. The radiation parameter, Grashof number, and second‐grade parameter cause a decrease in skin friction as their values increase. On the other hand, the suction, rotation, magnetic, dusty fluid, and Reynolds numbers cause a rise in skin friction.

Acoustic impedance characterization of sub-millimeter orifices exposed to grazing and grazing-bias flow

This paper characterizes the linear flow-acoustic impedance of circular sub-millimeter orifices exposed to a grazing and grazing-bias flow configuration using a multi-microphone three-port measurement framework. Measurements are performed for fully developed turbulent flows and the static aerodynamic pressure difference over the perforated plate is monitored and controlled. By counteracting any static pressure difference over the perforations, the effect of a purely grazing flow is studied and quantified using existing scaling laws. The increase in perforation resistance is observed to scale with Mach number, whereas a frequency dependent skin friction velocity correlation is seen to better fit the decreasing trend in equivalent length. However, for both impedance variables, the coefficients of the empirical macro-perforated models are revisited to match the measured data for sub-millimeter dimensions. In a grazing-bias flow configuration, the bias flow component is seen to dominate the perforation’s acoustic behavior for pressure differences larger than 100Pa. Furthermore, a pressure difference as low as 25Pa is observed to already significantly increase the resistance and decrease the equivalent length compared to the purely grazing flow situation and results in a different frequency dependency with respect to the orientation of the bias flow component. A such, the pressure difference over the perforations also becomes an important parameter to monitor in grazing flow measurements, especially for perforated plates with sub-millimeter dimensions and low percentage of open area.

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 %.

Engine oil blended Casson hybrid nanofluid flow along a uniformly heated curved surface with Arrhenius activation energy and suction: A computational study

The research studies the numerical analysis of an incompressible Casson hybrid nanofluid, composed of Fe3O4–Cu nanoparticles blended with engine oil, flowing over an exponentially stretched curved surface. It explores the effects of an aligned magnetic field, a uniform heat source, activation energy, and suction while maintaining a low Prandtl number. By employing appropriate similarity transformations, the original partial differential equations are converted into ordinary ones and solved using bvp4c in MATLAB. Graphs and tables depict the influence of dimensionless factors on skin friction coefficient, velocity, thermal, and concentration profiles, as well as Nusselt and Sherwood numbers. The computational findings reveal that magnetic field alignment significantly modifies velocity, decreasing it while uniformly enhancing temperature and concentration profiles. Casson fluid behavior in engine oil amplifies temperature and concentration profiles, thereby enhancing heat and mass transfer rates. Moreover, an increased heat source elevates temperature but reduces overall heat transfer. The chemical reaction parameter diminishes concentration, whereas activation energy enhances it, albeit impacting the mass transfer rate conversely. Additionally, suction increases flow resistance, while the stretching parameter exhibits an inverse effect, both positively influencing heat and mass transfer rates at higher values. Practically, these findings offer insights crucial for optimizing heat exchangers, biomedical devices, and cooling systems, enhancing their efficiency and performance. Additionally, they inform the design of industrial processes involving fluid flow, aiding in the development of more effective and sustainable solutions.

Magnetized Flow of Maxwell Fluid over a Slippery Stretching Reactive Surface with Thermophoretic Deposition

This manuscript investigated mathematically magnetized Maxwell fluid over slippery stretching reactive surface with thermophoretic deposition. Similarity transformation was used to recast partial differential equations modeling flow problem to nonlinear coupled ordinary differential equations which were solved using fourth order Range-Kutta method and Newton-Raphson shooting technique. Numerical results were compared with literature-based results and found to be in good accord. Skin friction coefficient, Nusselt number, Sherwood number, velocity profiles, temperature profiles and concentration profiles which are of importance to engineers, were found to be influenced by thermo-physical parameters governing the dynamics of flow. Their effects were illustrated in tabular form and graphically. The study found that increasing Thermophoretic deposition parameter, Momentum slip parameter and Biot number amplified rate of heat transfer but decreased rate of mass transfer and Skin friction coefficients. Thermal Grashof, Solutal Grashof, and Damkohler numbers reduced skin friction coefficients but increased heat and mass transfer rates.

Correlation between skin friction and enstrophy convection velocity in near-wall turbulence

The enstrophy convection velocity (denoted by uΩ) in the evolution equation of the boundary enstrophy is proportional to skin friction (denoted by τ) in an incompressible viscous flow, which can be determined globally as an optical flow problem from a time sequence of the boundary enstrophy fields. The correlation coefficient between |uΩ| and |τ| is evaluated in a turbulent channel flow at the friction Reynolds number Reτ=180, which is about 0.73 in the region of interest containing near-wall strong wall-normal velocity event associated with a sweep-ejection pair) and is approximately independent of the wall-normal coordinate in the viscous sublayer. This correlation coefficient is contributed mainly by strong near-wall coherent structures with high boundary enstrophy. The statistics of the difference between the normalized |uΩ| and |τ| are discussed. The statistical correlation between uΩ and τ elucidates the connection between near-wall flow structures and skin friction.

Thin film flow, heat transfer and viscous dissipation effects on vertical stretching sheet for different shapes of (Au-Np) dispersed in water

In this article, we present numerical investigation and analysis of thin film flow and heat transfer effects for different shapes of gold nanoparticles on a vertical stretching sheet. There are several uses for thin liquid films, including antireflection coating for lenses. Coating systems must have a smooth, polished surface, low friction, clarity, and strength to satisfy the demands of all of these applications. We consider thin film flow of nanoparticles on a vertical stretching sheet due to their numerous applications. Additionally, we employed water as the base fluid and considered different shapes of gold nanoparticles (blades, cylinders, and platelets). After formulating the problem, we convert nonlinear partial differential equations (PDEs) into ordinary differential equations (ODEs) using a transformation. The resulting nonlinear differential equations have been computed by the BVP4c method. It is examined and graphically assessed how the Nusselt number, temperature, skin friction, and fluid velocity are related. This research suggests that the blade shape has the maximum heat transfer rate and the lowest skin friction coefficient value.

Impact of Al2O3-Cu/Water Hybrid Nanofluid and Impinging Jet on Moving Plate at High Reynolds Numbers: A Numerical Study

Numerical research utilizing the commercial code ANSYS FLUENT is conducted to examine the heat transfer from a heated moving surface caused by confined slot-jet impingement at high Reynolds numbers. Confined slot-jet impingement's flow and thermal fields are studied using the SST k-wturbulence model. Important parameters such as high Reynolds numbers (50000, 100000, and 150000), different working fluids (water and 1.0% Al2O3-Cu/water hybrid nanofluid), and different impinging surface velocities (Vp=0, 2, and 3 m/s) are investigated on Nusselt numbers, skin friction factors, temperature contours, and velocity streamlines. According to the results, it is determined that the Nusselt number increased as the impinging surface’s velocity increased. While the Nusselt number grows with the increament in the Reynolds number, the skin friction factor tends to decrease. The utilization of 1.0% Al2O3-Cu/water hybrid nanofluid as the working fluid also has a substantial influence on heat transfer.

Non-Newtonian Slippery Nanofluid Flow Due to a Stretching Sheet Through a Porous Medium with Heat Generation and Thermal Slip

The domains of engineering, electrical, and medicine all have a significant demand for nanofluids. Applications for nanofluid flow include electronic device storage, industrial cooling and heating frameworks, and associated medicinal management information systems. Nanofluids are utilized generally as coolants in heat exchangers such as thermostats, electronic cooling systems, and radiators due to their enhanced thermal characteristics. This study aims to explain the mixed convection phenomenon’s applications on the thermal impact of Maxwell nanofluid. The mass diffusivity is supposed to be a function of concentration, whereas the thermal conductivity and viscosity of Maxwell nanofluid are assumed to be functions of temperature. It is recommended to consider the additional thermal effects of thermal slip, magnetic fields, and heat generation phenomena. The fluid flow motion was caused by the vertically stretched sheet. The dimensionless formulation of the suggested physical model is shown by the suitable variables interacting. The shooting approach is used in the numerical simulations, and it is based on lowering higher-order nonlinear differential equations to first-order. The slip velocity and the magnetic parameters have a direct impact on the local skin friction coefficient and velocity, as indicated by the research findings. Also, the increase in values of the Maxwell parameter, porous parameter, and viscosity parameter leads to the enhancement of temperature distribution, while the decline in velocity distribution can be attributed to the same factors. A comparison is also made with the results described in the literature that is currently available, and a superb agreement is discovered.

Boundary layer and heat transfer analysis of mixed convective nanofluid flow capturing the aspects of nanoparticles over a needle

Since their significance in commercial and scientific procedures has been recognized, studies regarding boundary layer flow and heat transfer have increased. The goal of this research is to examine the effects of hydromagnetic forces, mixed convection, and joule heating on ethylene glycol-based nanofluids suspended above a thin vertical needle. For thermal conductivity and viscosity, both aggregation and non-aggregation models are used. Here, we employed the similarity transformation to turn partial differential equations (PDEs) into dimensionless ODEs. Skin friction coefficients, Nusselt numbers, velocities, and temperature profiles were computed over a wide range of parameter values. The velocity and temperature profiles generated by the models that account for aggregation are superior to those generated by the homogeneous model. Velocity profile increases with λ and ε and decreases with M and e. Thermal profile increases with ϕ,M,e and Ec and decreases against λ. Skin friction and Nusselt number increases with increasing values of ϕ and λ towards ε. When comparing the findings from the present research to those from the past, it is clear that there is a high level of concordance between the two. Data availability“Data will be available on demand from Bilal.Ali”.

Unsteady thin film flow with ohmic heating and chemical reactions

In this study, we have analyzed magnetohydrodynamic (MHD) consequences on the heat and mass transmission within unsteady dissipated liquid film flow. Flow is generated due to stretchable surface accompanied with effects of ohmic heating, chemical reaction and heat absorption. Moreover, the flow governing partial differential equations (PDEs) are further modified into equivalent ordinary differential equations (ODEs) by applying regular perturbation method to get its analytical solution after that we have applied sixth-order Runge–Kutta technique to get its numerical solution. These two solutions are validating each other in the simulations. Figures are plotted to study the changes in physical quantities like skin friction coefficient, concentration, velocity, temperature, Sherwood and Nusselt number with the variations of Prandtl numbers Pr, parameters of chemical reaction [Formula: see text], Eckert numbers Ec, magnetic parameter Ha (also known as Hartman number) Schmidt number and coefficient of heat absorption [Formula: see text].

MHD flow of nanofluid over moving slender needle with nanoparticles aggregation and viscous dissipation effects.

The study of boundary layer flows over an irregularly shaped needle with small horizontal and vertical dimensions is popular among academics because it seems to have a lot of uses in fields as different as bioinformatics, medicine, engineering, and aerodynamics. With nanoparticle aggregation, magnetohydrodynamics, and viscous dissipation all playing a role in the flow and heat transmission of an axisymmetric nanofluid via a moving thin needle, this article provides guidance on how to employ a boundary layer for this purpose. In this case, we utilized the similarity transformation to change the dimensional partial differential equation into the dimensionless ordinary differential equation. We utilize MATHEMATICA to include shooting using RK-IV methods after identifying the numerical issue. Several characteristics were measured, leading to the discovery of a broad variety of values for things like skin friction coefficients, Nusselt numbers, velocity profiles, and temperature distributions. Velocity profile decreases with increasing values of and increases against Temperature profiles enhances with increasing values of , and The reduction in skin friction between a needle and a fluid can be observed when the values of M and are boosted. Furthermore, it was also noticed an increase in heat transfer on needle surface dramatically when , and M were raised, whereas displayed the opposite effect. The findings of the current study are compared with prior findings for a particular instance in order to confirm the findings. Excellent agreement between the two sets of results is found.

Analysis of heat transfer and thin film flow of Au−Np over an unsteady radial stretching sheet

The analysis of heat transfer and thin film flow over an unsteady radial stretching surface is the primary focus of this work. For the two-dimensional motion of the pair stress nanofluid made of gold nanoparticles, a mathematical model is put forth. Nonlinear governing partial differential equations for momentum and energy are converted into a set of ordinary differential equations via similarity transformations. By using the BVP4c method, the resulting nonlinear differential equations were calculated. The relationship between the Nusselt number, temperature, skin friction, and fluid motion velocity is examined and graphically analyzed. This study suggests that thin film thickness increases for rising values of volume fraction whereas it dropped for increasing values of the magnetic parameter and unsteadiness parameters Maximum heat transfer rate and skin friction coefficient has been observed for blade and cylinder shaped nanoparticles and minimum for brick shape.

MHD Casson nanofluid boundary layer flow in presence of radiation and non-uniform heat source/sink

&lt;abstract&gt;&lt;p&gt;On stretched magnetic surfaces, we present a numerical study of Casson nanofluids moving through porous materials. The Casson liquid model explains how non-Newtonian liquids behave. Numerical techniques are utilized to solve the nonlinear partial differential equations produced by similarity transformations. Results are gathered for the Nusselt number, skin friction coefficient, temperature and velocity. The impacts of physical variables on the flow and heat transfer characteristics of nanofluids are depicted in graphs. They include the Prandtl number, magnetic parameter, radiation parameter, porosity parameter and Casson parameter. Findings indicate that as the Casson nanofluid parameters are increased, the temperature profile rises but the velocity field decreases. With increasing magnetic parameters alone, it is possible to see a decrease in the thickness of the pulse boundary layer and an increase in the thickness of the thermal boundary layer. All the results are depicted in graphical representations.&lt;/p&gt;&lt;/abstract&gt;

Numerical Investigation of Suction/Injuction on Triple Diffusive MHD Casson Fluid Flow over a Vertical Stretching Surface

The article examines the characteristics of heat transfer for steady two-dimensional MHD Casson fluid with shear thickening properties in the presence of variable heat source for a vertical stretching sheet. The study considers the thermal radiation’s impact and velocity slip, and uses similarity transformations to convert the governing PDEs and corresponding boundary conditions into ODEs. Numerical solutions are obtained using shooting and R. K-4 methods, and the results presented for both injection and suction cases. The article examines the influence of various neutral parameters on the distribution of temperature, skin friction coefficient, velocity, and local Nusselt number, and presents the findings using tables and graphs. The study reveals that an increase in the Biot number and thermal radiation parameter results in an enhancement of the temperature distribution, while an increase in the suction/injection parameter causes a reduction in the velocity and temperature distributions for both injection and suction cases.

CFD Modeling for the Influence of Fly Ash Particle Size on the Different Properties of High Concentrated Slurry Transportation in Horizontal Pipe

The disposal of fly ash from thermal power plants is becoming a serious concern for environmental engineers. This article attempts to study the influence of particle size of the fly ash on the various properties of high concentrated slurry (50 - 70 % by weight) flow through a horizontal pipe with the help of a commercial CFD code ANSYS FLUENT. Modified Herschel-Bulkley model and SST k-ω turbulence model is used for computational analysis, and the computational outcomes are validated with the available literature. In the present study, the fly ash samples were procured from different coal-based thermal power plants. Various properties: physical and rheological are obtained experimentally. The specific gravity of particles and the static settling concentration (SSC) of the slurry increases with the decrease in the particle size. The rheological properties increase as the concentration increases, and the slurry behaves like a non-Newtonian fluid at a high concentration. In addition, the particle size and concentration intensively impact on the skin friction coefficient and velocity distribution. However, no significant impact on the velocity profile at 70 % concentration (by weight).&#x0D; HIGHLIGHTS&#x0D; &#x0D; The rheological properties increase as the concentration increases, and the slurry behaves like a non-Newtonian fluid at a high concentration&#x0D; CFD modelling of the slurry flow at high concentration with modified Herschel-Bulkley model and SST k-ω turbulence model&#x0D; The particle size and concentration intensively impact on the skin friction coefficient&#x0D; &#x0D; GRAPHICAL ABSTRACT

Impact of velocity slip and radiative magnetized Casson nanofluid with chemical reaction towards a nonlinear stretching sheet: Three-stage Lobatto collocation scheme

This paper examines the influence of magnetized Casson nanofluid flow and heat transport phenomena towards a boundary layer flow over a nonlinear stretchable surface. The characteristics of the nanofluid are illustrated by considering Brownian motion and thermophoresis effects due to which the fluid is electrically conducting. The nonlinear Casson model is very useful to describe the fluid behavior and the flow curves of suspensions of pigments in lithographic varnishes intended for the preparation of printing inks. A uniform magnetic field, along with suction and chemical reaction are taken into account. Similarity transformations are employed to convert the PDEs into ODEs, and then solved numerically (Bvp4c) using MATLAB. This scheme consists of a finite difference scheme that implements three-stage Lobatto IIIa collocation formula which provides continuous solution upto fifth-order accuracy. Excellent correctness of the present results has been acquired which is compared with the previous one. The outcomes of various parameters on heat transfer rate, skin friction coefficient, nanoparticle concentration, Sherwood number, velocity and temperature profiles are demonstrated via tabular forms and pictorially. The most important fact is that an increase in the thermophoresis parameter, radiation and magnetic parameter boosts up the fluid temperature, resulting in an improvement in the thermal boundary layer.

MHD heat and mass transfer nanofluid flow on a porous cylinder with chemical reaction and viscous dissipation effects: Benchmark solutions

The present study deals with a parametric study of heat and mass transfer of a steady, laminar, and 2D nanofluid flow under the influence of an inclined magnetic field, curvature, permeable medium, thermal radiation, electrical resistance heating, viscous dissipation, heat source/sink, chemical reaction, and concentration power-law exponent effects. Similarity transformations are employed to convert highly nonlinear PDEs to highly nonlinear ODEs. The Frobenius method was used to obtain the heat and mass transfer solutions in terms of hypergeometric function. Iron Oxide Black and water are used as the nanoparticles and base fluid, respectively. Heat and mass transfer boundary conditions are classified as PST (Prescribed surface temperature) and PSC (Prescribed surface concentration), respectively. The effects of nanoparticle volume fraction and curvature parameters on the local skin friction coefficient have been presented. The Box-Behnken design (BBD) is employed to demonstrate the effects of nanoparticle volume fraction parameter, Darcy number, and chemical reaction parameter on the local Sherwood number. Results show that the curvature parameter directly affects the local skin friction coefficient and velocity. In addition, with a rising concentration power-law exponent parameter, the thickness of the concentration boundary layer becomes thinner.