Entropy Generation Of Nanofluid Research Articles

Effect of magnetic field excitation and sinusoidal curved cavity coupling on heat transfer enhancement and entropy generation of nanofluids

Effect of magnetic field excitation and sinusoidal curved cavity coupling on heat transfer enhancement and entropy generation of nanofluids

Effects of velocity, thermal and concentration slips on the entropy generation of nanofluid over an inclined sheet

PurposeThis paper aims at studying numerically the entropy generation of nanofluid flowing over an inclined sheet in the presence of external magnetic field, heat source/sink, chemical reaction along with slip boundary conditions imposed on an impermeable wall.Design/methodology/approachA suitable similarity transformation technique has been used to convert the coupled nonlinear partial differential equations to ordinary differential equations (ODEs). The ODEs are then solved simultaneously using the finite difference method implemented through an in-house computer program. The effects of different controlling parameters such as magnetic parameter, radiation parameter, Brownian motion parameter, thermophoresis parameter, chemical reaction parameter, Reynolds number, Brinkmann number, Prandtl number, velocity slip parameter, temperature slip parameter and the concentration slip parameter on the entropy generation and Bejan number have been discussed comprehensively through the relevant physical insights for the first time.FindingsThe relative strengths of the irreversibilities due to heat transfer, fluid friction and the mass diffusion arising due to the change in each of the controlling variables have been delineated both in the near-wall and far-away-wall regions, which may be helpful for a better understanding of the thermo-fluid dynamics of nanofluid in boundary layer flows. The numerical results obtained from the present study have also been validated with results published in open literature.Originality/valueThe effects of different controlling parameters such as magnetic parameter, radiation parameter, Brownian motion parameter, thermophoresis parameter, chemical reaction parameter, Reynolds number, Brinkmann number, Prandtl number, velocity slip parameter, temperature slip parameter and the concentration slip parameter on the entropy generation and Bejan number have been discussed comprehensively through the relevant physical insights for the first time.

Effect of solid obstacle and thermal conditions on convective flow and entropy generation of nanofluid filled in a cylindrical chamber

PurposeOne of the major challenges in the design of thermal equipment is to minimize the entropy production and enhance the thermal dissipation rate for improving energy efficiency of the devices. In several industrial applications, the structure of thermal device is cylindrical shape. In this regard, this paper aims to explore the impact of isothermal cylindrical solid block on nanofluid (Ag – H2O) convective flow and entropy generation in a cylindrical annular chamber subjected to different thermal conditions. Furthermore, the present study also addresses the structural impact of cylindrical solid block placed at the center of annular domain.Design/methodology/approachThe alternating direction implicit and successive over relaxation techniques are used in the current investigation to solve the coupled partial differential equations. Furthermore, estimation of average Nusselt number and total entropy generation involves integration and is achieved by Simpson and Trapezoidal’s rules, respectively. Mesh independence checks have been carried out to ensure the accuracy of numerical results.FindingsComputations have been performed to analyze the simultaneous multiple influences, such as different thermal conditions, size and aspect ratio of the hot obstacle, Rayleigh number and nanoparticle shape on buoyancy-driven nanoliquid movement, heat dissipation, irreversibility distribution, cup-mixing temperature and performance evaluation criteria in an annular chamber. The computational results reveal that the nanoparticle shape and obstacle size produce conducive situation for increasing system’s thermal efficiency. Furthermore, utilization of nonspherical shaped nanoparticles enhances the heat transfer rate with minimum entropy generation in the enclosure. Also, greater performance evaluation criteria has been noticed for larger obstacle for both uniform and nonuniform heating.Research limitations/implicationsThe current numerical investigation can be extended to further explore the thermal performance with different positions of solid obstacle, inclination angles, by applying Lorentz force, internal heat generation and so on numerically or experimentally.Originality/valueA pioneering numerical investigation on the structural influence of hot solid block on the convective nanofluid flow, energy transport and entropy production in an annular space has been analyzed. The results in the present study are novel, related to various modern industrial applications. These results could be used as a firsthand information for the design engineers to obtain highly efficient thermal systems.

Experimental and support vector machine predictions of entropy generations and exergy efficiency of Fe3O4–SiO2/Water hybrid nanofluid in a plate heat exchanger

Several experiments of Fe3O4–SiO2/water hybrid nanofluids with volumetric concentrations ranging from 0.2 % to 1.0 % circulating in the cold-side of a plate heat exchanger at flow rates ranging from 0.05 kg/s to 0.1166 kg/s are performed. Under these ranges of flow rates and volumetric concentrations, the flow of Fe3O4–SiO2/water hybrid nanofluids remains laminar. The results of these experiments are predicted with support vector machine (SVM) algorithm to determine hybrid nanofluid entropy generation thermal, entropy generation frictional, and efficiency of exergy. Fe3O4–SiO2 nanomaterials was synthesized with reduction of chemicals and insitu development techniques, with XRD, FTIR and VSM instruments, characterizations were done. The SVM model gives large precision predictions of the measured data with correlations coefficients of 0.9944, 0.99798, and 0.99428 for frictional entropy generation, thermal entropy generation and exergy efficiency. At a flow rate of 0.1166 kg/s in the cold-side of PHE, the exergy efficiency is found to be 77.96 % for water (Reynolds number of 935.4) and with 1.0 vol% of Fe3O4–SiO2/water hybrid nanofluid in the cold-side of PHE, the efficiency is increased to 82.97 %, respectively. Under similar conditions of 0.1166 kg/s of flow circulation and 1.0 % vol. concentration of hybrid nanofluid, the thermal entropy generation is dropped off to 18.37 %, but the frictional entropy generation is increased by 20.97 %, compared to water, with the results that the total entropy generation drops off by 15.91 %, compared to water data. Preliminary curve-fitting correlations have been developed for the frictional entropy generation, thermal entropy generation, and exergy efficiency.

Natural convection and entropy generation of hybrid nanofluid in double annulus separated by a thin rotating partition under magnetic field

The present study analyzes the impacts of using a rotating partition on the natural convection and entropy generation of nanofluid filled double annulus under magnetic field by using finite volume method. Effects of various pertinent parameters such as Rayleigh number (Ra: 104 – 6×105), rotational Reynolds number (Rew: 0-100), Hartmann number (Ha: 0–60), fin height (Hf:0.1–0.5) and fin number (Nf:4–20) on the thermal performance improvements are numerically assessed. The contributions of rotations to the overall thermal performance become different depending upon the activation of rotations and magnetic field effects. Depending on whether rotations exist, magnetic field effects have different impact on the behavior of heat transport and entropy generation. Thermal performance reduction amounts become 40% without magnetic field when comparing the rotating and stationary interface cases. Fins further improve the thermal performance up to 23% depending upon the existence of magnetic field while rises with existence of magnetic field and increasing its strength for the case of non-rotating interface while it shows opposite behavior for rotating interface case. When the location of the interface becomes closer to the outer surface of the annulus, reduction of the entropy generation up to 68% can be obtained. Artificial neural network based model provides successful estimation of thermal performance and entropy generation when considering the impacts of rotating interface.

Numerical Simulation of MHD Natural Convection and Entropy Generation in Semicircular Cavity Based on LBM

To study the natural convection and entropy generation of a semicircular cavity containing a heat source under the magnetic field, based on the single-phase lattice Boltzmann method, a closed cavity model with a heat source in the upper semicircular (Case 1) and lower semicircular cavity (Case 2) is proposed. The cavity is filled with CuO-H2O nanofluid, and the hot heat source is placed in the center of the cavity. The effects of Rayleigh number, Hartmann number and magnetic field inclination on the average Nusselt number and the entropy generation of the semicircular cavity are studied. The results show that the increase in the Rayleigh number can promote the heat transfer performance and entropy generation of nanofluids. When the Hartmann number is less than 30, the increasing function of the Hartmann number at the time of total entropy generation reaches its maximum when the Hartmann number reaches 30. As the Hartmann number increases, the total entropy generation is the decreasing function of the Hartmann number. The larger the Hartmann number, the greater the influence of the magnetic field angle system. Under the same Hartman number, with the increase in the Rayleigh number, the flow function of Case 2 increases by 29% compared with that of Case 1. The average Nusselt number of heat source surfaces in Case 2 increases by 5.77% compared with Case 1.

Irreversibility analysis of melting rheology in micropolar Al2O3-mineral oil nanofluid flow with homogeneous and heterogeneous reactions

Mineral Oil [MO] has significant importance because of its vast variety of applications in various arenas of manufacturing, technology, and industrial processes. The applications of the Mineral Oil [MO] are PVC production, polystyrene production, as a lubricating, cutting fluid, thermoplastics rubber production, glossing product, wood products, cleaning products, lamp oil, glues, toys, veterinary, cosmetics, food preparation, as a brake fluid in some cars, and so forth. Due to these applications of Mineral Oil [MO], in the existing work, the two-dimensional mixed convective flow of micropolar fluid with the applications of the aluminum oxide nanoparticles in a Mineral Oil [MO] base liquid is taken into consideration. The melting heat phenomenon is discussed for the interpretation of heat transmission. Further, the flow analysis is discussed through the impacts of inclined magnetic field, heat generation, Joule heating and thermal radiation. Mass diffusivity is deliberated through the implementation of homogenous and heterogeneous chemical reactions. Entropic behavior is analyzed for the discussion of irreversibility analysis. Suitable similarity transformations are employed to renovate modeled systems of the PDEs into ODEs. Analytical simulation of the proposed model has been accomplished with the utilization of the homotopy analysis technique. Some significant outcomes from the existing work are that the velocity outline is reduced but the energy curve is greater for the melting parameter. Nanofluid entropy generation is increased due to the improvement of the Brinkman parameter and material parameter. Heat transportation is augmented due to the amplification of the radiation parameter, and nanoparticle volume fraction. The present study is useful in different fields of industries, technological processes, mechanical processes, and electrical processes due to the applications of mineral oil.

The application of two-phase model to assess the nanofluid entropy generation in serpentine and double-serpentine heatsinks

The frictional and thermal entropy generation rates (S˙fr and S˙th) of two heatsinks with serpentine (Conf. A) and double serpentine (Conf. B) channels with water/silver Nano fluid (NF) were numerically investigated. The results demonstrated that the augmentation of nanoparticle concentration (φ) from 0% to 1% leads to decrease S˙th by 6.36% and 3.51% in Conf. A and Conf. B, respectively, for Re=500. The escalation of Re from 500 to 2000 increases this percentages to 9.93% and 7.51%, respectively. Also, the increase of Re from 500 to 2000 at a constant φ reduces S˙th by 63% and 68% in Conf. A and Conf. B, respectively, due to enhance the heat dissipation. Moreover, the increasing of φ from 0% to 1% decreases S˙fr by 12.41% in both configurations and at four studied Res due to decreasing the NF velocity. Besides, the escalation of Re from 500-2000 intensifies S˙fr nearly by 62% and 67% in Conf. A and Conf. B, respectively. The entropy contour plots reveal that S˙fr intensifies near the turn regions of the serpentine channels. Also, S˙th is intensifies at the entrance of heatsink channels due to the high temperature gradient at these points. Conversely, S˙fr escalates at the exit of the channels due to intensification of the vortexes formed at the turn parts and along the serpentine channel.

Numerical simulation of entropy generation for nanofluid with the consequences of thermal radiation and Cattaneo-Christov heat flux model

Nanofluids have attracted a lot of attention as a result of their various manufacturing, technical, and medical purposes. The current investigation looks at the usage of Casson nanofluid in a permeable solar collector flow on an indefinite surface. Copper oxide-water (CuO − H2O), titanium dioxide-water (TiO − H2O), and disulfide molybdenum-water (MoS4 − H2O) nanofluids outcomes were all evaluated and expounded on as well. Copper oxide (CuO) nanoparticles have more elevated heat conductivity than titanium dioxide (TiO) nanoparticles, the Copper oxide-water (CuO − H2O) nanofluid demonstrated better heat transport capability than titanium dioxide-water (TiO2 − H2O) nanofluid. As the values of various parameters improve, the velocity, temperature, and entropy profiles of specified fluids grow and decrease, as shown in the graphical depictions. Using appropriate similarity adjustments, the governing partial differential equations were converted into nonlinear ordinary differential equations. The shooting technique is used in conjunction with the MATLAB software included with the bvp4c to compute a highly nonlinear system of equations. Graphs show the effects of key factors on velocity and temperature concentration. The temperature profile rises as shape factors rise. The temperature panel is decreasing as the Cattaneo-Christov component increases. By increasing the influence of the Biot number, both temperature and entropy profiles are rising. The conclusions for Casson nanofluid are analyzed using the parameterized development of the Cattaneo-Christov component. These findings are helpful for the thermic control of heat transmission in upcoming technologies. Finally, the dynamics of fluid flow are investigated using streamlines.

Entropy analysis of the unsteady Darcian nanofluid flow in a cylindrical pipe with a porous wall

This work examines the entropy generation of nanofluids flowing through a porous medium in a permeable pipe. Water-based suspensions with Cu, Al2O3 and TiO2 as nanoparticles are used as working fluids. These fluids have been found to have enhanced heat transfer characteristics which can be beneficial in various applications such as refrigeration, engine cooling and optimising heat transfer systems. The equations governing the flow system are formulated, and the solution is obtained using the Runge–Kutta–Fehlberg scheme. Results obtained in this flow regime provide unique insight into the flow quantities. Alumina-water is relatively efficient and performs much better regarding heat transfer efficiency and entropy minimisation. However, it exhibits the highest skin friction at the pipe wall. This result is more enhanced when the nanoparticles' solid volume fraction is increased. Irreversibility due to heat transfer is more pronounced and becomes dominant near the pipe wall when the nanoparticles' solid volume fraction is reduced.

Optimization of blade geometry by neural network in natural convection and entropy generation of nanofluids within an oblique square cavity with the effects of volumetric radiation with LB method

Optimization of blade geometry by neural network in natural convection and entropy generation of nanofluids within an oblique square cavity with the effects of volumetric radiation with LB method

Experimental Analysis of Double Pipe Heat Exchanger with V-cut Twisted Tape Inserts using PCM Dispersed Nanofluids

The performance of a double tube heat exchanger with V-cut twisted tape inserts (VCTT) and phase change material (PCM) dispersed nanofluid is investigated experimentally. The three water-based Al2O3, PCM, and Al2O3+PCM nanofluid with different concentrations (0.01-0.1% vol.) are used. The impacts of different geometric parameters, i.e., twist ratio (TR), depth ratio (DR) and width ratio (WR) of VCTT inserts on Nusselt number (Nu), friction factor (f) and entropy generation are examined. The outcomes expose that Nu and f increase as particle concentration increases and twisting ratio decreases. A higher Nu and f are generated by a higher DR or a lower WR. In all cases, the entropy generation of nanofluid is found to be lower than that of water. For all working fluids, a rise in TR, a fall in DR, and a rise in WR increases overall entropy generation.

MHD double-diffusive mixed convection and entropy generation of nanofluid in a trapezoidal cavity

Double diffusive, Magnetohydrodynamics (MHD), mixed convection flow of Al2O3-water nanofluid inside a trapezoidal enclosure with discrete heat and mass source at the bottom wall of the cavity has been discussed numerically. Together with these entropy generations due to fluid friction, heat transfer, mass transfer and magnetic field are discussed. The upper wall of the cavity is considered to move with a fixed velocity U0 towards positive X-direction. Different inclination angles and different aspect ratios are considered in the present study. Second and fourth order finite difference approximations are used to solve the governing equations by using biconjugate gradient stabilized method (BiCGStab). It is observed that, entropy generation mostly depends on heat transfer and lower values of Richardson number (Ri=0.01) reduces the entropy generation. The highest quantitative value of |Sθ|max is 21,664 for Ri=100,Re=100andϕ=450 and lowest quantative value of |Sθ|max is 5,824 for Ri=0.01,Re=1000andϕ=600 throughout the present study. Also the highest quantitative values of average Nusselt and Sherwood numbers are 0.2597 and 0.4208 for Ri=10,Re=100andϕ=45∘. The main objective of our present study is to minimize entropy generations due to combined effects of fluid flow, heat transfer, mass transfer and the effect of magnetic field so that the loss of energy can be reduced. This study observed that mixed convection flow, low magnetic field and low aspect ratio cavity of rectangular shape is always preferable to reduce total entropy generation and the middle part of the lower wall of the cavity is highly acceptable for heat and mass source for sprinkle of heat and mass throughout the whole of the cavity.

Natural convection of nanofluids in solar energy collectors based on a two-phase lattice Boltzmann model

In order to improve the photothermal conversion efficiency of solar energy collectors, the laminar convection of nanofluids in five types of solar energy collectors was numerically studied with a two-phase lattice Boltzmann model. In the current simulation, Cu–water nanofluids (volume fraction φ = 0.3%) were chosen. The equilibrium distribution function with D2Q9 model and the boundary conditions of nonequilibrium extrapolation scheme were applied to establish the lattice Boltzmann model. The effects of different Rayleigh numbers (Ra = 104–106), structures (rectangle cavity, trapezoid cavity and parallelogram cavity) and aspect ratios (A = 2:1, 4:3 and 1:1) of solar energy collectors on the heat transfer were considered. The temperature distribution, streamline and entropy generation of nanofluids in the solar energy collectors were analyzed. Results demonstrated that the increase in Rayleigh number heightens the heat convection of nanofluids. The trapezoid cavity and parallelogram have a special structure, which will form a flow dead zone, weaken the heat transfer effect and determine the position of maximum entropy generation.

Impact of local elasticity and inner rotating circular cylinder on the magneto‐hydrodynamics forced convection and entropy generation of nanofluid in a U‐shaped vented cavity

This study analyzes the effects of a partial elastic wall and rotating circular cylinder on the convective heat transfer of carbon nanotube (CNT)–water nanofluid filled U‐shaped cavity with entropy generation by considering inclined magnetic field effects. Numerical simulation is performed by using ALE with finite element method (FEM). Impacts of various important parameters such as Re number, Ha number, magnetic field orientation, elastic wall size and modulus, angular velocity, and horizontal position of the rotating cylinder on the forced convection are analyzed. When the values of Re number, strength of magnetic field (up to Ha number of 50), and orientation angle are increased, the average Nu value rises while the impact is opposite for higher elastic wall size and horizontal position of the cylinder above 0.4H. When the rotational cylinder effects are considered, enhancement up to 60% is obtained at the highest speed as compared to motionless cylinder case. The average Nu variation is in the range of 9%–10.45% at the highest value when varying the size and modulus of the elastic wall. Flexible wall effects on the average Nu number variation becomes more pronounced when the angular rotational velocity is highest at the clockwise rotation and for the highest Re number. The average Nu number enhancements are 13%–14% at the highest Ha number. The entropy generation rates with varying Ha number, rotational velocity, and location of the cylinder are different for the left and right parts of the domains while impacts of elastic wall properties on the entropy generation rate are slight.

Numerical investigation of conjugate heat transfer and entropy generation of MHD natural convection of nanofluid in an inclined enclosure

PurposeThe purpose of this paper is to investigate conjugate heat transfer of natural convection and entropy generation of nanofluid in the presence of external magnetic field via numerical approach in an inclined square cavity enclosure.Design/methodology/approachControl volume finite volume method with collocated arrangement of grids was used for discretization of continuity, momentum, solid and fluid energy equations. Rhie and Chow interpolation technique was applied to avoid checkerboard problem in pressure field and the well-established SIMPLE algorithm was followed to deal with the pressure and velocity coupling. The cavity is filled with water and nanoparticles of the aluminum oxide (Al2O3). This study has been conducted for the certain pertinent parameters of the volume fraction of nanoparticle (φ = 0–0.08), the angle of inclination (ϴ = 0°–330°), the Ra number (Ra = 103–108), the solid to fluid conductivity ratio (ksf = 1–400), the Ha number (Ha = 0–80) and the wall thickness ratio (δ/L = 0–0.3).FindingsThe results indicate that averaged Nu number increases by approximately 9% by increasing volume fraction from 0.0 to 0.08. Nu increases with an increasing inclination angle to 40° and decreases abruptly in 90° because of the formation of two weaker vorticity with opposite circulation pattern intensifying the density of isotherm curves in a vertical direction. Nu increases sharply with increasing Ra more than 105. Nu also augments almost 67% by increasing ksf = 1 to ksf = 50 and remains constant by increasing ksf more than 50. Nu number reduction is almost 72% with a variation of wall thickness ratio from d/L = 0 to 0.3. Entropy generation because of fluid flow, magnetic field and heat transfer reduces linearly almost 30%, 19% and 16% by increasing volume fraction, respectively. With increasing ksf, entropy generation because of fluid flow, magnetic field and heat transfer increases asymptotically, but Bejan number decreases.Originality/valueA brief review of conducted research studies in nanofluid flow and heat transfer reveals that the effect of wall thermal inertia was not investigated in MHD natural convection of nanofluids in an inclined enclosure. The aim of the present study is to analyze conjugate heat transfer in an inclined cavity filled with water and Al2O3.

Inclined magneto: convection, internal heat, and entropy generation of nanofluid in an I-shaped cavity saturated with porous media

A numerical investigation of entropy generation due to MHD-free convective of Cu–water nanofluid in a porous I-shaped cavity is reported. The cavity is under Darcy law with inclined uniform magnetic field. The cavity is cooled from the top and a part of bottom wall subjected to uniform heat flux, while the other parts of walls of the cavity are adiabatic. Mathematical pattern formulated employing the single-phase nanofluid approach in governing equations the problem has been solved by finite difference technique. Prime efforts have been concentrated on the impacts of the pertinent parameters on the fluid flow and heat transfer inside the cavity. Numerical data have been plotted in the form of streamlines, isotherms, and average Nusselt numbers. The results show that the Nu number decreases via increasing the Ha number. It increases when the Ra number is increased. The maximum and minimum values of Nusselt occur at B = 0.2 and B = 0.8, respectively. Exerting an angle for magnetic flux leads to the improvement in thermal performance for all amount of B. The effects of Ha, nanofluid volume fraction, heat source size, location and angle of magnetic field on heat transfer, entropy generation, and thermal performance are completely studied and discussed.

Impact of surface texture on entropy generation in nanofluid

We consider a heat transfer augmentation problem to minimize the entropy generation by assuming boundary-layer flow of nanofluid over a moving wavy surface. The nanofluid demonstrates great potential in enhancing the heat transfer process due to its high thermal conductivity. The famous Tiwari and Das model has been used in the present article. Two types of water based nanofluids containing Cu and Fe3O4 nanoparticles are considered. Moreover, the surface texture is taken to be sinusoidal wavy to improve the thermal contact. The governing equations are transformed into a system of non-similar PDE by using suitable dimensionless variables and solved by the Keller-Box method. The effects of involved parameters like amplitude wavelength ratio, group parameters, and volume fraction on the total entropy number and the Bejan number are analyzed graphically. It is showed Fe3O4 base nanofluid is more effective to lessen the entropy production as compared to Cu base nanofluid.

Influence of rotation angle of a triangular tube with a built‐in twisted tape on the thermal‐exergy efficiency and entropy generation of nanofluids in the heat exchange system

AbstractIn order to investigate the thermal‐exergy efficiency and entropy generation of nanofluids flowing through a triangular tube with a built‐in twisted tape, a heat exchange system is designed and established. Deionized water and three mass concentration nanofluids (ω = 0.1 wt%, 0.3 wt%, and 0.5 wt%) are applied as the heat‐transfer mediums flowing through three different rotation angle (α = 0°, 30°, and 60°) triangular tubes, respectively. Thermal efficiency index (η) and entropy generation (S) are used to characterize the performance of the heat exchange system. It is proved that the increase of nanoparticles can not only effectively promote the heat transfer effect but also augment the pressure loss. Nusselt number of nanofluids is increased by 20.2% on average, whereas the flow resistance coefficient is increased by 10.1% on average. Based on the thermal efficiency index, the data demonstrate that ω = 0.5 wt% nanofluids in the triangular tube at α = 0° can make the most effective use of energy, whose value could reach 1.32 at most. Exergy efficiency of nanofluids in the heat exchange system can be evidently heightened under the same pumping power and flow rate. Entropy production of 0.1 wt% nanofluids is the smallest.

Investigation of entropy generation in nanofluid’s axisymmetric stagnation flow over a cylinder with constant wall temperature and uniform surface suction-blowing

Dimensionless temperature, Nusselt number and entropy generation in stagnation flow of incompressible nanofluid over an infinite cylinder accompanying uniform suction and blow in steady state have been investigated in this study. Free stream has been steady as well with the initial stream rate of k¯. Dimensional analysis and similarity solution of Navier-stokes and energy equations have been presented. These equations are simplified implementing appropriate transformations introduced in this research. The similarity equations are solved where the cylinder’s wall is under constant Temperature. All these solutions are acceptable for Reynolds numbers Re=k¯a2/2υf of 0.1–1000, various dimensionless surface diffusion S=Uo/k¯a and specific volume fractions of nano particles where a is the cylinder radius and υf is the kinematic viscosity of the base-fluid. The results show that for all Reynolds numbers, diffusion depth of radial and axial components of velocity field and wall shear stress increases as a result of decline in nano particles volume fraction and growth in surface diffusion. Moreover, increase in nano particles volume fraction and surface suction raises heat transfer coefficient and Nusselt number. Also the largest amount of entropy generated is calculated.