Dissipative Effects Research Articles

2-µm energy-managed soliton fiber laser.

To generate energetic short pulses from fiber laser oscillators in the 2-µm emission window, we here propose an alternative to the conventional methods of pulse stretching and dispersion management. We build a passively mode-locked fiber laser from anomalous single-mode fibers and utilize strong dissipative effects to delineate high and low pulse energy sections within the cavity. Whereas the main laser output delivers low-chirp sub-ps pulses with an energy up to 12 nJ, the intracavity pulse is reshaped into a ∼0.1-nJ conventional soliton, stabilizing the laser dynamics while enabling a wide tunability in both repetition rate and central emission wavelength.

Thermal performance analysis of magnetohydrodynamic Al[formula omitted]O[formula omitted]-SiO2-TiO[formula omitted]/water ternary hybrid nanofluid in converging and diverging channels with nanoparticle shape effects

Improving heat transfer in thermal systems is critical to achieving better results in a variety of systems. The study aims to investigate the laminar flow dynamics of Al2O3-SiO2-TiO2/water hybrid nanofluids, emphasizing how the channel geometry affects the velocity, temperature distribution, and heat transfer efficiency. This understanding is crucial for optimizing industrial processes, such as cooling systems and heat exchangers. Effects of various nanoparticle shapes, joule heating, viscous dissipation, thermal radiation, and heat source/sink on the system’s behavior are evaluated. Governing partial differential equations are transformed into ordinary differential equations using similarity variables and are solved semi-analytically via the homotopy analysis method. As the Hartmann number increases from 1 to 7, the heat transfer rate rises from 0.02% to 0.9%. When the radiation parameter and Eckert number are varied from 0.05 to 0.2, the heat transfer rate increases significantly, from 1.2% to 4.86% and 3.43% to 13.73%, respectively. Heat transfer rate increased by 16.28% with heat source (Q=2) and decreased by -16.12% with heat sink (Q=−2). Platelet-shaped nanoparticles demonstrate lower skin friction in divergent channels, whereas spherical nanoparticles exhibit higher skin friction; this trend reverses in convergent channels. Suspensions of nanoparticles with a 5% volume fraction achieve heat transfer rates of 1.88%, 4.07%, 10.54%, 19.20%, and 8.74% for spheres, bricks, cylinders, platelets, and blades, respectively. The study reveals that Al2O3/H2O, Al2O3-TiO2/H2O, and Al2O3-SiO2-TiO2/H2O nanofluids have the best heat transfer rates for mono nanofluid, hybrid nanofluid, and ternary hybrid nanofluid by 15.24%, 19.92%, and 19.20%, respectively. Finally, multiple linear regression is employed to analyze the impact of relevant parameters on heat transfer rate and skin friction.

Thermal and irreversibility analysis of non-Newtonian fluid within trapezoidal cavity containing heated cylinder

In this article, the mixed convection transport of the Carreau fluid in the presence of a magnetic field and a heated circular cylinder within a trapezoidal cavity is examined. Finite element analysis is used via COMSOL Multiphysics software to simulate the two-dimensional flow. The heat equation is formulated by incorporating the effects of viscous dissipation and Joule heating. The upper and lower surfaces of the cavity are adiabatic, while the left and right sides are assumed to be cold. The temperature distribution and flow field within the cavity are visualized through the plotting of isotherms, streamlines, and total entropy generation. The graphical representations are performed to examine the impacts of physical parameters on temperature, flow field, and total entropy generation, including the Reynolds number , Weissenberg number ( 1.0 ≤ We ≤ 6.0 ) , Power law index ( 0.1 ≤ n ≤ 5.0 ) , Hartman number ( 1.0 ≤ M ≤ 50 ) , and Richardson number ( 0.2 ≤ Ri ≤ 5.0 ) and ( 0.2 ≤ Rc ≤ 0.8 ) . It is found that the Joule heating and Richardson number are the main reasons to increase the thermal performance within the cavity. The r ( 100 ≤ Re ≤ 500 ) ising values of power law index and Weissenberg numbers caused to reduce the velocity field, irreversible effects and circulation within cavity. While the entropy is augmented by elevating the Eckert and Hartmann numbers. Furthermore, heat transfer improved with the increased magnetic field and Eckert number.

Electroosmotic mechanism of Ellis fluid with Joule heating, viscous dissipation and magnetic field effects in a pumping microtube.

The dynamics of electro-osmotically generated flow of biological viscoelastic fluid in a cylindrical geometry are investigated in this paper. This flux is the result of walls contracting and relaxing sinusoidally in a magnetic environment. The rheology of the fluid is accurately captured with the Ellis fluid (blood) model. Both Joule heating and viscous dissipation are accounted for during thermal analysis. The electric potential induced in the EDL is obtained by applying the Debye-Huckel linearization to the non-linear Poisson-Boltzmann equation. Mathematical modelling is incorporated in cylindrical coordinates in wave frame of reference. Assuming a long wavelength characterized by a low Reynolds number, the Ellis fluid model's governing equations are simplified. Subsequently, the differential equations that result are computed numerically utilizing the NDSolve utility that is integrated into Mathematica. Graphical representations are utilized to visually and comprehensively assess the thermal characteristics, flow features, heat transfer coefficient, and skin friction coefficient. Various factors are taken into consideration, including the impact of Ellis fluid parameters, electric double layer, magnetic field, Brinkman number, and Ohmic dissipation. Ellis fluid's axial velocity boosts with a rise of the electroosmotic parameter and power-law index while decreasing with an increase in the Hartmann number and material fluid parameter. The fluid temperature is directly proportional to EDL parameter and parameters of Ohmic and viscous dissipation. The current model may be used in clinical scenarios involving the gastrointestinal system and capillaries, electro-hydrodynamic therapy, delivery of drugs in pharmacological, and biomedical devices.

Unified linear response theory of quantum electronic circuits

Modeling the electrical response of multi-level quantum systems at finite frequency has been typically performed in the context of two incomplete paradigms: (i) input-output theory, which is valid at any frequency but neglects dynamic losses, and (ii) semiclassical theory, which captures dynamic dissipation effects well but is only accurate at low frequencies. Here, we develop a unifying theory, valid for arbitrary frequencies, that captures both the small-signal quantum behavior and the non-unitary effects introduced by relaxation and dephasing. The theory allows a multi-level system to be described by a universal small-signal equivalent-circuit model, a resonant RLC circuit, whose topology only depends on the number of energy levels. We apply our model to a double-quantum-dot charge qubit and a Majorana qubit, showing the capability to continuously describe the systems from adiabatic to resonant and from coherent to incoherent, suggesting new and realistic experiments for improved quantum state readout. Our model will facilitate the design of hybrid quantum–classical circuits and the simulation of qubit control and quantum state readout.

Numerical Assessment of the Thermal Performance of Microchannels with Slip and Viscous Dissipation Effects

Microchannels are widely used across various industries, including pharmaceuticals and biochemistry, automotive and aerospace, energy production, and many others, although they were originally developed for the computing and electronics sectors. The performance of microchannels is strongly affected by factors such as rarefaction and viscous dissipation. In the present paper, a numerical analysis of the performance of microchannels featuring rectangular, trapezoidal and double-trapezoidal cross-sections in the slip flow regime is presented. The fully developed laminar forced convection of a Newtonian fluid with constant properties is considered. The non-dimensional forms of governing equations are solved by setting slip velocity and uniform heat flux as boundary conditions. Model accuracy was established using the available scientific literature. The numerical results indicated that viscous dissipation effects led to a decrease in the average Nusselt number across all the microchannels examined in this study. The degree of reduction is influenced by the cross-section, aspect ratio and Knudsen number. The highest reductions in the average Nusselt number values were observed under continuum flow conditions for all the microchannels investigated.

Constant-roll warm inflation within Rastall gravity

This research paper used a newly proposed strategy for finding the exact inflationary solutions to the Friedman equations in the context of Rastall theory of gravity (RTG), which is known as constant-roll warm inflation (CRWI). The dissipative effects produced during WI are studied by introducing a dissipation factor Q=Γ3H, where Γ is the coefficient of dissipation. We establish the model to evaluate the inflaton field, effective potential requires to produce inflation, and entropy density. These physical quantities lead to developing the important inflationary observables like scalar/tensor power spectrum, scalar spectral index, tensor-to-scalar ratio, and running of spectral-index for two choices of obtained potential that are V0=0 and V0≠0. In this study, we focus on the effects of the theory parameter λ, CR parameter β, and dissipation factor Q (under a high dissipative regime for which Q=constant) on inflation, and are constrained to observe the compatibility of our model with Planck TT+lowP (2013), Planck TT, TE, EE+lowP (2015), Planck 2018 and BICEP/Keck 2021 bounds. The results are feasible and interesting up to the 2σ confidence level. Finally, we conclude that the CR technique produces significant changes in the early universe.

Heat and mass flux dynamics of tangent hyperbolic nanofluid flow with unsteady rotatory stretching disk over Darcy-Forchheimer porous medium

Abstract The purpose of the research is to examine a tangent hyperbolic nanofluid flowing in three dimensions (3D) axisymmetrically on an unsteady rotatory stretching disk over a Darcy-Forchheimer porous medium. First order initial value problems (IVPs) are generated from the governing partial differential equations (PDEs) through the use of similarity transformation and linearization. The Runge-Kutta sixth order (RK6) is utilized to solve the IVP system using the shooting technique and the built-in Python program ‘fsolve model10’. Articles that have already been published are used to validate the implemented approach. Graphs are used to examine how various parameters affect velocity, temperature, and concentration. Additionally, the behavior of heat, mass flux, and skin friction in response to different parameters is investigated. The study’s findings showed that as the Forchheimer number and velocity slip parameter increased, the nanofluid’s radial and tangential velocities decreased as well. As temperature and concentration slip parameters increase, correspondingly, thicker and thinner boundary layer structures are seen. The drag force in the tangential and radial direction behaves in the same manner. Both the rates of heat and mass transfers are initiated for an increase Eckert and Prandtl numbers and demotivated for power-law index number. The dissipation effect with radiation and chemical reaction plays a major role in heat and mass fluxes, respectively. The study can be used in various computer storage, coatings, lubricants, and coolants.

Coupling analysis between wave resonance in the moonpool and heave motion of the twin hulls with mooring effect

Fluid resonance in the moonpool formed by two identical rectangular hulls in water waves is investigated by employing the Computational Fluid Dynamics (CFD) package OpenFOAMⓇ. The influence of vertical stiffness on the behavior of moonpool resonance coupling with the heave motion response is presented. Numerical simulations show that the free surface oscillation in the moonpool exhibits a two-peak variation with the incident wave frequency, defined as the first and second peak frequencies. A local Keulegan–Carpenter (KC) number is introduced for describing the influence of fluid viscosity and flow rotation on the fluid resonance and heave motion resonance. At the first peak frequency, the free surface oscillation and heave motion response show an in-phase relationship, where increase in the vertical stiffness can increase the relative motion between them. This finally leads to an increase in the KC number, indicating the increased effect of energy dissipation with increase in the vertical stiffness. At the second peak frequency with an out-of-phase relationship between the free surface oscillation and heave motion response, the variation of the KC number is not sensitive to the vertical stiffness. Correspondingly, the influence of energy dissipation is not strongly dependent on the vertical stiffness.

A study on the optimization of cooling performance for oil-immersed transformers in high temperature environments utilizing response surface methodology

To enhance the thermal efficiency of self-cooling oil-immersed transformers in high-temperature environments, this study proposes a method to improve heat transfer by disrupting the boundary layer through incorporating a V-shaped raised structure on the inner wall of the transformer. Numerical calculations using COMSOL software were conducted to compare and analyze the effects of four distinct geometric shapes of protrusions on the thermal performance of 35 kV self-cooling oil-immersed transformers. The results demonstrate that among these four structures, the cone-shaped raised structure exhibits optimal heat dissipation effect and effectively mitigates winding operating temperature. Building upon this finding, response surface methodology was employed for experimental design, constructing a response surface model with minimum winding operating temperature as an objective function while considering variables such as longitudinal spacing (P), height (e), and transverse spacing (g) of cone-shaped protrusions. Through analysis, optimal geometric parameters for cone-shaped raised structures were determined. This research provides an effective solution to address energy consumption and low efficiency issues prevalent in traditional oil-immersed radiators.

DUFOUR, SORET AND DISSIPATION EFFECTS ON MAGNETOHYDRODYNAMIC FLOW PAST A STRETCHING PERMEABLE SHEET WITH RADIATIVE CHEMICAL REACTION ANDHEAT SOURCE

Present investigation explores the numerical solution of Magnetohydrodynamic laminar steady gray fluid flow with heat and mass transfer past a stretching permeable sheet, incorporating several factors such as heat source, viscous and joules dissipation effects, thermal radiation, chemical reactions, Soret and Dufour effects. The governing nonlinear PDEs are simplified into ODEs with the help of similarity transformations. Momentum equation is solved analytically. Non-Dimensional temperature and concentration calculated with the help of RK- shooting method with Nachtsheim-Swigert iteration method. Key results include the calculation of heat and mass transfer rates and Co-efficient of skin friction. The effects of various parameters such as magnetic field strength, suction, radiation, chemical reactions, internal heat generation and dissipative effects on the flow characteristics and other physical parameters are thoroughly investigated, highlighting their impact on the thermal and concentration profiles in the system. This comprehensive analysis provides insights into the behaviour of the fluid flow under the specified conditions, which can be useful for applications in engineering and industrial processes.

Heat transfer enhancement in magnetohydrodynamic hybrid nanofluids over a Bi-directional extending sheet with slip and convective conditions

The hybrid nanofluids can enhance cooling systems in microelectronics by enhancing heat dissipation from processes which makes them vital for maintaining optimal performance. They are also beneficial in solar systems where efficient heat transfer is essential for exploiting the energy detention. Thus, this study has studied the three-dimensional flow of a water-based hybrid nanofluid comprising of Fe3O4 and CuO nanoparticles on a bi-directional extending sheet. The bi-directional extending sheet is subjected to thermal convective and velocity slip conditions. In addition, the effects of heat source, magnetic field, thermal radiation, viscous dissipation, and Joule heating are employed. The partial differential equations (PDEs) that represent the mathematical model are subsequently converted to ordinary differential equations (ODEs) by applying the appropriate similarity variables. The shooting technique is incorporated to determine the computational solution of the converted ODEs. The effectiveness of the current study is confirmed by published results, which also validate the current outcomes. Based on the results, it is concluded that CuO and Fe3O4 solid nanoparticle volume fractions improved the thermal distribution while decreasing the velocity distributions along x and y-axes. The thermal distribution is improved by the thermal heat source, thermal radiation, thermal Biot number, and thermal Eckert numbers. CuO-water nanofluid has a higher velocity panel than CuO-Fe3O4/water hybrid nanofluid. Conversely, the CuO-Fe3O4/water hybrid nanofluid has a higher thermal profile than the CuO-water nanofluid. CuO-water nanofluid flow has higher surface drags than CuO-Fe3O4/water hybrid nanofluid flow. CuO-water nanofluid has a lower heat transfer rate than CuO-Fe3O4/water hybrid nanofluid.

Fatigue-induced alterations in force production, trajectory and performance in alpine skiing

ABSTRACT In giant slalom, the ability to apply a high amount of force in the radial direction is essential for performance. A race is characterized by repeated turns performed at high velocity, potentially inducing fatigue. Therefore, this study aimed to assess the effect of fatigue on performance, trajectory characteristics, and force production capacities onto the snow. Twelve skiers ran a 4-turn section with (FATIGUE) and without pre-induced fatigue (CONTROL). Knee extensor maximal voluntary contraction (MVC) was performed before the experiment and after both conditions. Section time, energy dissipation, path length, total force output, force application effectiveness, and EMG activity of the main lower-limb muscles were compared between conditions. Multiple linear regressions were used to understand whether interindividual variability in the kinematic, kinetic and EMG between conditions explains variability in performance changes with fatigue. MVC was lower after FATIGUE (−19.1 ± 6.4%, p < 0.001) but did not change after CONTROL. FATIGUE was associated with longer section times (+0.21 ± 0.11 s, p < 0.001), energy dissipation (−0.78 ± 1.05 J.s.kg.m−1, p = 0.026), path length (+1.1 ± 1.6 m, p = 0.033) and lower force application effectiveness (−0.1 ± 0.1, p = 0.017). This study experimentally demonstrates that fatigue in giant slalom results in lower force application effectiveness, inducing over-dissipation of mechanical energy and longer path length, leading to lower performance.

Heat Transfer Characteristics of a Quiescent Fluid over a Moving Flat Surface

Optimizing thermal control methods and enhancing the efficiency of various engineering processes, such as the cooling of hot moving surfaces, is imperative. Therefore, it is crucial to investigate heat transfer and temperature distributions across moving surfaces in stationary fluids. In this study, the combined effects of viscous dissipation, temperature-dependent viscosity, and a moving surface in a quiescent fluid on the temperature and velocity profiles are investigated. A two-dimensional steady laminar boundary layer flow of an incompressible Newtonian fluid, driven by the movement of the surface where viscosity is an inverse function of temperature, is analyzed. The effects of flow parameters, including Reynolds number, Eckert number, Prandtl number, variable viscosity, and surface velocity on temperature and velocity profiles, are determined. The governing boundary layer partial differential equations are transformed into non-dimensional form and solved using the central finite difference numerical method, implemented in MATLAB software. The numerical results demonstrate that an increase in the Reynolds number and the variable viscosity parameter leads to an increase in the velocity profiles. Additionally, an increase in Reynolds number, Prandtl number, variable viscosity, and surface velocity leads to a decrease in temperature profiles. Finally, an increase in the Eckert number results in higher temperature profiles. Therefore, with suitable flow parameters, the temperature of the fluid can be regulated. These findings are useful in cooling hot sheets or metallic plates drawn over a quiescent fluid to obtain high-quality final products.

Effects of exponentially stretching sheet for MHD Williamson nanofluid with chemical reaction and thermal radiative

This paper explores the combined effects of heat radiation, viscous dissipation, and chemical reactions on the steady flow of Williamson nanofluid over an exponentially stretched sheet. The Governing non-linear Partial Differential Equations (PDE's), converted to couple nonlinear Ordinary ODE's by using similarity transformation, which are solved numerically using the Runge-Kutta-Fehlberg method along with the shooting technique. The study shows detailed analysis of the behaviour of Williamson nanofluid under the influence of thermal radiation and magnetic fields, having relevant industrial applications in cooling technologies and polymer processing. The results show that increasing the magnetic field parameter reduces the fluid velocity, while higher thermal radiation and Brownian motion parameters significantly enhance heat transfer rate withing the boundary region.

Seismic Response Characteristics of a Utility Tunnel Crossing a River Considering Hydrodynamic Pressure Effects

As a long lifeline system of buried structures, the utility tunnel (UT) is vulnerable to earthquake invasion. For utility tunnels with inverted siphon arrangements crossing rivers, the seismic response is more complex due to the basin effect of acceleration in the topography and the influence of fluctuating hydrodynamic pressure, but there is currently a gap in targeted seismic response analyses and references. Based on a UT project in Haikou, this paper studied seismic responses of a cast-in-place UT considering the coupled model of water–soil–tunnel structure on ABAQUS software. Herein, the dynamic fluctuation of hydrodynamic pressure is simulated using an acoustic–solid interaction model. A viscoelastic artificial boundary was used to simulate the soil boundary effect, and seismic loads were equivalent to nodal forces. Considering seismic invading direction and varying water elevation, this paper investigates the dynamic response characteristics and damage mechanisms of river-crossing utility tunnels. This study shows that the basin effect causes the soil acceleration around the UT to show variability in different sections, and the amplification factor of the peak acceleration at the central location is almost doubled. The damage and dynamic water pressure of the UT are intensified under bidirectional seismic excitation, and the damage location is concentrated at the junction of the horizontal section and the vertical section. Bending moments and axial forces are the main mechanical behaviors along the axial direction. Changes in river levels have a certain positive effect on the UT peak MISES, DAMAGEC, and SDEG, and it exhibits a certain degree of energy dissipation and seismic damping effect. For the aseismic design of cross-river cast-in-place utility tunnels, bidirectional seismic calculations should be performed, and the influence of river hydrodynamic pressure should not be neglected.

Investigation of comparative entropy in different nanofluids inspired by solar radiations and unsteady effects: Model analysis for permeable channel

Entropy analysis in nano as well as conventional fluids is of paramount interest and highly affected by the active physical quantities. The research provides comprehensive comparative entropy performance of multiple nanofluids in the view of model quantities. The physical model considered in the presence of solar radiations, dissipation energy and magnetic field. The multiple fluids squeezed in a channel formed by two horizontal sheets with upper non-stationary surface. The entropy modeling performed using similarity variables for transient flow and governing laws. The numerical approach (RK method coupled with shooting scheme) is used for entropy results which obtained for ternary, hybrid, nano and base fluids. It is found that entropy optimized in ternary nanofluid while hybrid, nano and common fluids caused reduction in it. Dissipation effects (Ec=0.1,0.3,0.5,0.7) increases the entropy while significant reduction is observed for Ω1=0.1,0.2,0.3,0.4. The solar radiations in the range of Rd=1.0 to Rd=7.0 contributes effectively to improve entropy phenomena in both inward and outward plate movement. Thus, the system can be maintained at low entropy by strengthening the effects of Ω1 and optimum entropy is subject to Eckert number, α=0.1,0.2,0.3,0.4, radiations (Rd=1.0,3.0,5.0,7.0) for S>0.0 and S<0.0, respectively.

Suppression of quantum dissipation: a cooperative effect of quantum squeezing and quantum measurement.

The ability to isolate a quantum system from its environment is of fundamental interest and importance in optical quantum science and technology. Here we propose an experimentally feasible scheme for beating environment-induced dissipation in an open two-level system coupled to a parametrically driven cavity. The mechanism relies on a novel, to the best of our knowledge, cooperation between light-matter coupling enhancement and frequent measurements. We demonstrate that, in the presence of the cooperation, the system dynamics can be completely dominated by the effective system-cavity interaction, and the dissipative effects from the system-environment coupling can be surprisingly ignored. This work provides a generic method of dissipation suppression in a variety of quantum mechanical platforms, including natural atoms and superconducting circuits.

Computational analysis of unsteady oscillatory flow of nanofluid with variable electric conductivity: gear-generalized differential quadrature approach

Abstract This study numerically investigated the entropy production in nanofluids’ dissipative unsteady oscillatory flow characterized by variable electric conductivity and magnetic heating effects. The imposition of the non-isothermal boundary condition on the oscillatory stretching sheet plays a crucial role in establishing the self-similar solution in the presence of viscous heating. An external magnetic field (uniform in space and time) is imposed perpendicular to the plane of the oscillating stretched boundary. The energy equation, incorporating viscous dissipation effects and momentum equation, is reduced to nonlinear coupled partial differential equations and numerically solved using the Gear-generalized differential quadrature scheme.Additionally, to ensure the precision and reliability of the outcomes, the numerical code undergoes a thorough validation process that involves comparing its outputs to the findings of previous available studies. The Corcione model is implemented to describe the nanofluid’s effective viscosity and thermal conductivity. Furthermore, expressions for entropy production and relative irreversibility parameter (Bejan number), considering variable electric conductivity, are derived and computed based on solutions obtained from momentum and energy equations. The impacts of parameters such as magnetic parameter, variable electric conductivity parameter, Eckert number, Strouhal number, Prandtl number and temperature difference parameters on flow, heat transfer, entropy generation, and Bejan number are systematically illustrated and examined. We observed that increasing the variable electric conductivity parameters reduces the velocity profiles while improving the thermal fields. Similar behavior is found when the strength of a magnetic field is increased. The skin friction coefficient exhibits an augmentation in response to the Eckert number, dimensionless time, Strouhal number, nanoparticle volume fraction, magnetic parameter, and variable thermal conductivity parameter. Conversely, the Nusselt number increases concerning the Strouhal number and nanoparticle volume fraction. At the same time, it declines in association with the magnetic parameter, dimensionless time, Eckert number, and variable electric conductivity parameter.This comprehensive investigation enhances our understanding of nanofluid dynamics and provides valuable insights for optimizing thermal management systems across various engineering disciplines.

MHD Free Convection Boundary Layer Flow on a Horizontal Circular Cylinder in a Williamson Hybrid Ferrofluid with Viscous Dissipation

The present research examined the flow of a horizontal circular cylinder immersed in a Williamson hybrid ferrofluid via free convection boundary layer flow. The fluid flow is modelled by means of governing partial differential equations that incorporate viscous dissipation and magnetohydrodynamic (MHD) effects. Prior to being converted into a more practical partial differential equation, these dimensional equations are reduced to a non-dimensional form by utilising appropriate dimensionless variables. The Keller-box approach is then used to solve these equations with fewer dependent variables numerically. Graphical representations are generated, and the impacts of different interested factors are analysed using MATLAB software. According to the results, the hybrid ferrofluid outperformed ferrofluid with the same particle volume fraction in terms of skin friction and convective heat transfer capabilities.