Presence Of Viscous Dissipation Research Articles

Estimation of entropy optimization in Darcy-Forchheimer flow of Carreau-Yasuda fluid (non-Newtonian) with first order velocity slip

This research article elaborates the salient attributes of sundry variables i.e., Darcy-Forchheimer number, mixed convection parameter, porosity parameter, Weissenberg number, slip parameter, Prandtl number, activation energy parameter and chemical reaction parameter on the forced convective Darcy-forchheimer flow of non-Newtonian fluid (Carreau-Yasuda fluid) subject to stretchable and flat surface of the sheet. A general mathematical form of the entropy generation rate for Carreau-Yasuda fluid is derived in the presence of porosity irreversibility, fluid friction irreversibility, heat transfer irreversibility and Joule heating irreversibility through second law of thermodynamics. The fluid flow is saturated and magnetized through Darcy-Forchheimer porous medium and applied magnetic field. The energy equation is modeled in the presence of viscous dissipation. Series solutions are calculated by semi analytical method HAM. The behavior of pertinent flow parameters is discussed graphically. The main interest in giving to the engineering curiosity like velocity gradient and Nusselt number. The main theme of this research communication is to enhance the information of entropy optimized flow and heat and mass transport, and to inspire the investigators and analysts to scrutinize gradually innovative attributes that can take improvement on the entropy generation minimization.

Thermokinetic transport of dilatant/pseudoplastic fluids in a hydrophobic patterned micro-slit

The flow enhancement and convective heat transfer along with entropy generation analysis are studied numerically in a micro-slit with alternating hydrodynamic slip patches. The advances in molecular simulations and micro-scale experiments confirmed that the slip of fluid on the solid surfaces occurred at small scale flows and the traditional no-slip boundary conditions cannot be applicable for the flow simulation at the micro- and nano-scale. The coupled Poisson–Boltzmann–Navier–Stokes equations dealing with an external electric potential are involved for the flow enhancement and entropy generation analysis of non-Newtonian fluids in a micro-slit with periodic slips. From the finite volume simulation, it is observed that the drag force effect is very strong along the wall for the transportation and mixing of fluids. This effect is found to be minimized by imposing periodic hydrophobic slippage along the boundary. An additional pressure gradient is generated by imposing electrokinetic pumping, resulting in a higher velocity gradient in the flow direction in the presence of viscous dissipation and Joule heating effects. The results are predicted in terms of the flow enhancement factor (Ef) (which provides maximum species transport), the average heat transfer rate (Nu), and the average entropy generation due to fluid friction, heat transfer, and Joule heating effects. The advantages and disadvantages of utilizing slip conditions are discussed, which has large scale applications on drug delivery and DNA analysis and sequencing, since cell damage due to pumping will be minimized.

COMBINED EFFECT OF THERMAL RADIATION AND VISCOUS DISSIPATION ON UNSTEADY FREE CONVECTIVE MAGNETO-HYDRODYNAMIC FLOW THROUGH AN IRREGULAR CHANNEL

This study is focused on the joint effects of thermal radiation and magnetic field on an unsteady flow of natural convective, electrically conducting fluid past an irregular vertical channel in the presence of viscous dissipation. The magnetic field is applied normal to the channel. The coupled ordinary differential equations (ODE) are obtained using perturbation technique on the dimensionless governing equations involving energy and momentum equation. Semi-analytical solutions are obtained for the resultant coupled ODE with the application of Adomian Decomposition Method (ADM) with the aid of Mathematica 11.0 software. The pertinent flow parameters in velocity, temperature, Skin-friction and Nusselt number are discussed and exhibited using tables and graphs. It is revealed that at all regions, thermal radiation and viscous dissipation have a tendency to accelerate the Skin-friction and heat transfer coefficient of the fluid.

Impacts of variable thermal conductivity and mixed convective stagnation‐point flow in a couple stress nanofluid with viscous heating and heat source

AbstractThe current study examines mixed (combined) convection stagnation‐point couple stress nanofluid over a stretched cylinder of variable thermal conductivity in the presence of viscous dissipation and internal heat source. The basic governing partial differential equations have been converted to coupled nonlinear differential equations by using adequate similarity transformations. By applying semi‐analytic technique (BVPh2.0), the equivalent ordinary differential equations are successfully solved and validated with a bvp4c solver. Graphs are presented to study the impact of various parameters on axial velocity, temperature, and volumetric nanofluid concentration profiles. The coefficient of skin friction (quantifying resistance) and the rate of heat and mass transfer on the surface due to flow variables are computed and explained. The axial velocity and momentum thickness are decreased with increasing couple stress parameter, whereas the reverse trend is noted with mixed convection and buoyancy ratio parameters. The temperature distribution increases for increasing Brownian motion and thermal conductivity parameter, whereas it decreases for increasing stagnation parameter.

Thermal analysis of electroosmotic flow in a vertical ciliated tube with viscous dissipation and heat source effects

Thermal analysis of electroosmotic flow of Newtonian fluid in the presence of viscous dissipation and heat source in a vertical ciliated tube is discussed. Three different cases of electroosmotic flow with heat source, viscous dissipation and buoyancy effects are presented, and their solutions are calculated analytically. Exact solutions for velocity and temperature field are calculated for the first case (presence of heat source and buoyancy force) and second case (presence of viscous dissipation), but the approximate solution is calculated by the Adomian decomposition method for the third case (presence of buoyancy force and viscous dissipation). The modeled equations of electroosmotic flow are reduced into simple equations by the long wavelength and low Reynolds number approximation. Influences of physical parameters are graphically computed for axial velocity, temperature profile, pressure gradient and stream function. It is observed that electroosmosis shows the significant effect on velocity and temperature profile in the presence of viscous dissipation and buoyancy force. This mathematical model gives a deep understanding to describe the thermal analysis in biomimetic ciliary flow and for the efficient flow of highly viscous fluid due to artificial cilia on glass tube used in laboratory.

Effects of Viscous Dissipation on Mixed Convection Boundary Layer Flow Past a Vertical Moving Plate in a Nanofluid

Adaptation from the thermal management applied in modern engine cooling system and central processing unit (CPU) in performance computer devices, present study solved the problem of steady mixed convection boundary layer flow and heat transfer on a moving vertical plate in a nanofluid with the presence of viscous dissipation and constant wall temperature. The mathematical model which is in non-linear partial differential equations is solved numerically by similarity transformation approach with the Keller-box method. The characteristics and effects of pertinent parameters considered which are Prandtl number, Lewis number, Eckert number, Brownian motion parameter, thermophoresis parameter, mixed convection parameter, concentration mixed convection parameter and plate velocity parameter are analyzed and discussed. In conclusion, there exist dual solutions in opposing flow for moving parameter range 0.18 0.48.    Further, the increase of mixed convection parameter in assisting flow results to the increase in the Nusselt number and skin friction coefficient.

Mixed convective slip flow of hybrid nanofluid (MWCNTs + Cu + Water), nanofluid (MWCNTs + Water) and base fluid (Water): a comparative investigation

Here, we addressed comparative investigation of hybrid nanofluid (MWCNTs + Cu + Water), nanofluid (MWCNTs + Water) and base fluid (Water). Flow is due to curved sheet. Flow via slip boundary condition is examined. Heat transport analysis is carried out in the presence of viscous dissipation, mixed convection and convective boundary condition. Transformation procedure is adopted for converting PDEs (continuity eq., momentum eq., energy eq. and boundary conditions) into ODEs. These nonlinear coupled ODEs are solved via shooting method with RK-4 algorithms (bvp4c). Behaviors of involved parameters on flow, Nusselt number (heat transfer rate), temperature and skin friction coefficient are analyzed graphically. Velocity of fluid enhances with increment in nanoparticles volume fraction for multi-walled CNTs, nanoparticle volume fraction for Cu and mixed convection parameter, while it can be reduced via higher estimations of velocity slip parameter. Temperature of the fluid varies directly with an increase in nanoparticles volume fraction for multi-walled CNTs, nanoparticle volume fraction for Cu, Eckert number and thermal Biot number. Skin friction coefficient is reduced via higher mixed convection as well as velocity slip parameters. Nusselt number intensifies with increment in nanoparticles volume fraction for multi-walled CNTs, nanoparticle volume fraction for Cu, Eckert and thermal Biot numbers. During comparative study amongst hybrid nanomaterial, nanomaterial and base fluid, efficient behavior is noted for hybrid nanomaterial.

Three-dimensional mixed convection flow with variable thermal conductivity and frictional heating

In this article, three-dimensional mixed convection flow over an exponentially stretching sheet is investigated. Energy equation is modelled in the presence of viscous dissipation and variable thermal conductivity. Temperature of the sheet is varying exponentially and is chosen in a form that facilitates the similarity transformations to obtain self-similar equations. Resulting nonlinear ordinary differential equations are solved numerically employing the Runge–Kutta shooting method. In order to check the accuracy of the method, these equations are also solved using bvp4c built-in routine in Matlab. Both solutions are in excellent agreement. The effects of physical parameters on the dimensionless velocity field and temperature are demonstrated through various graphs. The novelty of this analysis is the self-similar solution of the three-dimensional boundary layer flow in the presence of mixed convection, viscous dissipation and variable thermal conductivity.

Performance of heat transfer in MHD mixed convection flow using nanofluids in the presence of viscous dissipation: Local non-similarity solution

In this study, an investigation has been carried out to examine the effects of thermal radiation, heat generation/absorption, viscous dissipation and suction parameter on MHD flow of water-base nanofluid (Ag, Cu, Al2O3, CuO and TiO2). This study also focused on the mixed convective flow of water-base nanofluid due to a vertical permeable plate in the presence of convective boundary condition. Further, heat transfer has been inspected for water-base fluid influenced by heat generation/absorption and viscous dissipation. Moreover, the governing equations are reduced to nonlinear ordinary differential equations via Sparrow–Quack–Boerner local non-similarity method. These nonlinear ODEs are simulated numerically by means of Runge–Kutta–Fehlberg method (RKF-45). The impact of pertinent parameters on the dimensionless velocity, nanofluid temperature, skin friction and local Nusselt number are discussed and displayed. The results match with a special case of formerly available work. The present exploration exhibits that nanoparticle volume fraction increases the velocity and temperature of Cu-water nanofluid. It is also shown that magnetic parameter reduces the heat transfer rate.

Couette flow and heat transfer of heat-generating/absorbing fluid in a rotating channel in presence of viscous dissipation

Theoretical investigation is carried out on flow formation and heat transfer characteristics of viscous incompressible and heat-generating/absorbing fluid in a horizontal rotating channel in presence of viscous dissipation. Exact solution is obtained for two cases of interest: when the fluid considered is heat generating and also when the fluid is heat absorbing. Interesting effect of some governing parameters on fluid temperature, rate of heat transfer and critical Eckert number are identified and discussed using line graphs and tables for both cases. It is found out that the rate of heat transfer decreases with increase in heat source causing an increase in fluid temperature while the contrast is true for heat sink. In addition, critical Eckert number decreases with heat source while it increases with heat sink.

NUMERICAL SOLUTION OF MAGNETOHYDRODYNAMIC (MHD) RADIATIVE BOUNDARY LAYER FLOW AND HEAT TRANSFER ALONG A WEDGE IN THE PRESENCE OF SUCTION/INJECTION

An approximate numerical solution for the two dimensional laminar MHD radiative boundary layer flow along a wall of wedge with appropriate suction and injection in the presence of viscous dissipation and porous medium is considered in the present article. The fluid is considered to be viscous and incompressible. By applying appropriate similarity transformation, the governing flow equations have been transformed into corresponding higher order ordinary differential equations. The flow model is shown to be controlled by a number of flow parameters, viz. the radiation parameter, magnetic parameter, the permeability parameter, Prandtl number, Eckert number, the Hartree pressure gradient parameter and suction-injection parameter. The system of governing differential equations is solved numerically by shooting method and numerical calculations are carried out for different values of above mentioned dimensionless parameters. An analysis of the drawn results predicts that the velocity boundary layer and thermal boundary layer are influenced appreciably by the suction-injection, radiation and viscous dissipation at the wall of wedge.

Radiation and Heat Source Effects on MHD Free Convection Flow over an Inclined Porous Plate in the Presence of Viscous Dissipation

This study analyzes radiation, viscous dissipation and heat source effects on magneto-hydrodynamic free convection flow, of a viscous incompressible fluid over an inclined porous plate. Applying the perturbation technique, the solution of a set of ordinary differential equations are gotten as a result of reducing the non-linear partial differential equations of motion, energy and diffusion, which is solved analytically for velocity, temperature and the concentration distribution. The effect of Radiation, viscous dissipation and heat source on the velocity, temperature, concentration, skin friction, heat transfer and rate of mass flux distribution is plotted graphically using Mathematica 12 software and discussed. It is observed that increased Magnetic field reduces the velocity profile, increases the temperature, skin friction and heat transfer profile. Increase in radiation reduces heat transfer causing a mixed effect on the velocity, temperature and skin friction while an increase in the heat source causes a turbulent effect on the velocity, temperature and skin friction profile. Increase in porosity reduces the velocity, temperature, skin friction and heat transfer profile and finally parameters such as Chemical reaction, Grashof concentration number and Schmidt number had no effect on the velocity, temperature, skin friction and heat transfer profile.

Analysis of fully developed mixed convection in open-ended annuli with viscous dissipation

The vertical, open-ended double-passage annular space between three vertical concentric co-axial cylinders is an important geometry representing significant number of industrial applications. For a design engineer, the knowledge of fully developed mixed convection in this geometry is very essential. Hence, in this paper, it is proposed to numerically as well as analytically investigate the fully developed mixed convective flow in the vertical annuli having two annular passages with open upper and lower boundaries by taking viscous dissipation into consideration. The prime objective of the analysis is to bring out the influences of the location of middle cylinder, known as baffle, and viscous dissipation on the fluid flow and temperature profiles as well as the associated thermal transport rates. By neglecting the viscous dissipation influences, exact solutions are determined, while the finite difference-based numerical solutions are achieved in the presence of viscous dissipation. Further, excellent agreement is obtained between the analytical and numerical solutions under limiting conditions. The roles of viscous dissipation and baffle location are meticulously brought out through the flow pattern, temperature profiles and heat transport rates.

Effects of Viscous Dissipation and Wall Conduction on Steady Mixed Convection Couette Flow of Heat Generating/Absorbing Fluid

This article theoretically investigated mixed convection flow of heat generating/absorbing fluid in the presence of viscous dissipation and wall conduction effects. The flow is considered to be steady in a vertical channel with some boundary thickness. One of the plates is heated while the other is kept at ambient temperature. The governing flow equations were solved analytically using Homotopy Perturbation Method (HPM). The influences of the governing parameters were captured in graphs, tables and a table was constructed for validation of the work. It is worthwhile to stress that, both the velocity and temperature profiles decrease near the heated plate with an increase in boundary thickness (<i>d</i>) while the reverse cases were observed toward the cold plate. The velocity profile increases near the heated plate with increase in mixed convection parameter (<i>Gre</i>) and decreases towards the cold plate. Rate of heat transfer has been observed to decrease with increase in boundary plate thickness (<i>d</i>) while the critical value of (<i>Gre</i>) increases with growing boundary plate thickness. The study therefore established the importance of boundary plate thickness in mixed convection investigation.

MHD Boundary Layer Flow and Heat Transfer of Nano fluid over a Vertical Stretching Sheet in the Presence of a Heat Source

The nanoparticles used in nanofluid are prepared for carbides and oxides. In this paper, a nanofluid flow over a stretching sheet in the presence of viscous dissipation, heat source, and magnetic field was numerically explored with the help of the Runge-Kutta shooting technique and the effects of various parameters were analyzed using graphical representation.

Stability analysis and multiple solution of Cu–Al2O3/H2O nanofluid contains hybrid nanomaterials over a shrinking surface in the presence of viscous dissipation

Researchers are using different types of nanomaterials for the enhancement of the thermal performance of regular fluids such as water, kerosene oil, etc. However, these days, the researchers are more interested in hybrid nanomaterials. The purpose of this communication is to examine the stability analysis of Cu–Al2O3/water hybrid nanofluid over a non-linear shrinking sheet. The hybrid nanomaterials are composed of Cu and Al2O3. These hybridized nanomaterials are then dissolved in water taken as base fluid to form Cu–Al2O3//water hybrid nanofluid. Mathematical analysis and modeling have been attended in the presence of viscous dissipation and suction/injection effects. The governing equations of mathematical models are transformed into self-similar solutions in the form of ODEs by using similarity transformation. Solutions of the non-linear ODEs are created by employing of three-stage Lobatto IIIa formula which is built-in BVP4C function in the MATLAB software. A comparison of the current study has been done with the preceding published literature. The distributions of velocity, temperature profiles, coefficient of skin friction and heat transfer rate are presented graphically and conferred for numerous significant parameters entering into the problem. Results revealed the existence of dual solutions for a certain range of the suction/blowing parameter. Stability analysis is also done in order to obtain dual solutions stability. The smallest eigenvalues suggest that the first solution is stable from the second solution. Hybrid nanomaterials have a high scope toward nurturing our day-to-day life.

Forced convective heat transfer of nonlinear viscoelastic flows over a circular cylinder at low Reynolds inertia regime

In this paper, the forced convective heat transfer of viscoelastic fluid flow around a circular cylinder at a low Reynolds number is studied numerically. The effect of viscous dissipation on the problem is modeld which is the main innovative aspect of present study. The Phan–Thien–Tanner (PTT) model is used as the nonlinear constitutive equation. To avoid divergence and stabilize the numerical process in high elastic cases, the log-conformation approach is used. The results indicated that the Nusselt number (Nu) monotonically increases with increasing elasticity number (El), retardation ratio (β), Prandtl number (Pr), and Brinkman number (Br) in a wide range. Both drag reduction (for El < 0.025) and drag enhancement (for El > 0.025) were seen in the numerical results. In high elastic flow regime (El > 10), due to the increased storing nature of viscoelastic fluid compared to the dissipative nature, drag coefficient (CD) and Nu become constant, which causes the fluid to behave like a Newtonian fluid. The temperature-dependent properties were also investigated for all of fluid property, and the large effects of viscosity, and relaxation time were seen in hydrodynamic and thermal parameters. The contribution of normal stresses in viscous dissipation (VD) is much lower than shear stress, due to the lower values of corresponding components in deformation tensor. The elasticity influences the heat transfer by two mchanisms of convection empowering as an indirect way and viscous dissipation as a direct way. Increasing El, β, and ξ increases Nu via the convection mechanism (even at Br = 0), while Nu is decreased with ε. However, Nu increases with the variations of all the parameters, in presence of viscous dissipation. It was also seen that the heat transfer direction changes for Br > 90. Finally, the effects of El, β, ε, ξ, Pr, and Br on the distribution of stress components, velocity, temperature, Nu, and CD were investigated. Two accurate correlations were proposed for the variations of CD and Nu against El, which were validated for a wide range of El.

Entropy optimized CNTs based Darcy-Forchheimer nanomaterial flow between two stretchable rotating disks

Here entropy optimized CNTs based flow of viscous liquid is addressed between two stretchable surfaces of disks. Both upper and lower disks stretch and rotate with different rates and angular frequencies. Carbon nanotubes (single and multi-walls) are considered as a nanoparticles and water as continuous phase liquid. Xue model is utilized in the mathematical modeling for the transport of nanoparticles. Energy expression is developed through first law of thermodynamics and discussed in the presence of viscous dissipation. Main attention is given to the modeling of entropy generation subject to CNTs nanoparticles. Total entropy rate is calculated. Average residual error is calculated through implementation of optimal homotopy analysis method. Flow parameters are graphically discussed for both single and multi-walls carbon nanotubes. Furthermore, engineering quantities like skin friction and Nusselt number are numerical calculated and discussed through Tables. From obtained outcomes it is examined that entropy rate boosts up versus larger Brinkman number and nanoparticles volume friction. No such attempt is yet done by the researchers on entropy optimized Darcy-Forchheimer CNTs based nanomaterial flow between two rotating disks. The obtained outcomes are compared with published literature and found good agreement.

Estimation of magnetohydrodynamic radiative nanofluid flow over a porous non-linear stretching surface: application in biomedical research.

The present study investigates the effects of thermal radiation and chemical reaction on magnetohydrodynamic flow, heat, and mass transfer characteristics of nanofluids such as Cu-water and Ag-water over a non-linear porous stretching surface in the presence of viscous dissipation and heat generation. Using similarity transformation, the governing boundary layer equations of the problem are transformed into non-linear ordinary differential equations and solved numerically by the shooting method along with the Runge-Kutta-Fehlberg fourth-fifth-order integration scheme. The influences of various parameters on velocity, temperature, and concentration profiles of the flow field are analysed and the results are plotted graphically. A backpropagation neural network is applied to predict the skin friction coefficient, Nusselt number, and Sherwood number and these results are presented through graphs. The present numerical results are compared with the existing results and are found to be in good agreement. The results of artificial neural network and the obtained numerical values agree well with an error <5%.

Second law analysis of Blasius flow with nonlinear Rosseland thermal radiation in the presence of viscous dissipation

In the present article, we perform the second law analysis of classical Blasius flow accounting the effects of nonlinear radiation and frictional heating. The two-dimensional boundary layer momentum and energy equations are converted to self-similar equations using similarity transformations. The set of resultant ordinary differential equations are solved numerically. The numerical results obtained from solutions of dimensionless momentum and energy equations are used to calculate the entropy generation number and Bejan number. The velocity profile f'(ξ), temperature distribution θ(ξ), entropy production number Ns and Bejan number Be are plotted against the physical flow parameters and are discussed in detail. Further, for the sake of validation of our numerical code, the obtained results are reproduced using Matlab built-in boundary value solver bvp4c resulting in an excellent agreement. It is observed that entropy generation is increasing function of heating parameter, Prandtl number, Eckert number and radiation parameter. Further, it is observed that entropy generation can be minimized by reducing the operating temperature ΔT=Tw−T∞.