Nanofluid Inlet Temperature Research Articles

Heat Transfer and Fluid Flow Characteristics in a Micro Heat Exchanger Employing Warm Nanofluids for Cooling of Electronic Components

The heat transfer enhancement and hydrodynamic characteristics of nanofluid use in a micro heat exchanger is investigated for cooling electronic components working in hot climatic conditions. The cooling fluid employed was water and TiO2 nanoparticles at mass concentrations of 1% and 5%, the Reynolds numbers ranged from 400 to 2000, and the inlet temperatures ranged between 35 °C and 65 °C. At a nanofluid inlet temperature of 55 °C and a nanoparticle concentration of 1%, the Nusselt number increased by 23% up to 54% as the Reynolds number varied between 400 and 2000. At a nanoparticle concentration of 5%, the percentages that correspondingly enhanced the Nusselt number were 32% and 63%. The temperature of the electronic heating component decreased by 4.6–5.2 °C when the nanofluid concentration was increased from 0 to 5% at a Reynolds number of 400 and a nanofluid inlet temperature of 35 °C. Small increments in the pressure drop of about 6% and 13% were observed at nanofluid concentrations of 1% and 5%, respectively. With nanoparticle concentrations of 1% and 5%, a Reynolds number of 2000, and a nanofluid inlet temperature of 35 °C, performance evaluation criterion (PEC) values of 1.36 and 1.45 were obtained. When the nanofluid inlet temperature increased to 65 °C, the PEC parameter decreased to 1.02–1.10 for both concentrations.

Thermo-hydraulic performance of metal oxide nanofluid flow through the helical coil tube of a three-fluid heat exchanger: an experimental and optimization study

ABSTRACT The thermo-hydraulic performance of a three-fluid heat exchanger (TFHE) to concurrently transfer heat from a heated nanofluid to ordinary water and air is the subject of investigation in this paper. The fluid flow and heat transfer abilities of the TFHE concerning changes in nanofluid (Al2O3-water, CuO-water, Fe2O3-water) are used to quantify effectiveness and pressure drop. Parametric studies having nanofluid volume fraction (1%, 5%, and 10%), flow rate (100LPH, 150LPH, and 200LPH), and inlet temperature (80°C, 120°C, and 160°C) respectively are considered in the present experimentation. The results of the experiment demonstrate that the use of CuO-water nanofluid at an intake temperature of 160°C and 5% volume percentage led to a considerable improvement in heat transfer effectiveness, with a maximum value of 0.884. At a flow rate of 100 LPH, a volume percentage of 1%, and an inlet temperature of 160°C, the Al2O3-water nanofluid exhibits the least amount of pressure loss. Nine test runs with four control factors are conducted using Taguchi’s experiment design. From Taguchi analysis, it is observed that the nanofluid volume flow rate and nanofluid inlet temperature have the largest and lowest contributions of 68.83%, 3.76%, and 72.05%, 2.03% respectively on heat transfer effectiveness and pressure drop of the TFHE. A multi-response optimization is carried out using the Taguchi-Gray Analysis to determine the least pressure drop and the highest possible heat transfer effectiveness. At 1% volume fraction, 100 LPH volume flow rate, and 160°C intake temperature, Al2O3-water nanofluids show an increase in the total performance of the TFHE of 10.39%.

Performance analysis of a nanofluid spectral splitting concentrating PV/T system with triangular receiver based on MCRT-FVM coupled method

Optimizing system structure is one promising way to enhance the spectral beam splitting concentrating photovoltaic/thermal (SBS CPV/T) system performance. In this study, a linear Fresnel CPV/T system incorporated with triangular cooling duct and Ag@SiO2/ethylene glycol (EG) nanofluid filter is designed to enhance the overall performance of the system. To quantitatively reflect the heat generation of Ag@SiO2/EG nanofluid filter and silicon PV modules under inhomogeneous solar flux distributions, a coupled method combining Monte Carlo ray tracing (MCRT) method with Finite Volume Method (FVM) is employed. After validating the coupled method, the performance of the system with triangular receiver is discussed under various operating conditions. The results demonstrate that the nanofluid outlet temperature and PV module temperature present 316.3 K and 306.8 K at nanofluid inlet temperature of 298 K, respectively. The high mass flow rate and low inlet temperature allow high thermal and total efficiencies, while they present slight effect on electrical efficiency. To quantify the achievable enhancements with the triangular receiver, a SBS CPV/T system with flat-plate receiver is also discussed. It is found that the total efficiency of the triangular receiver is higher than that of the flat-plate receiver, with a maximum enhancement of 7.9%.

Effects of Reynolds Number on the Volume Concentration of Al2O3 in Ethylene Glycol

The nanofluid is suspension of nanoparticles in the base fluid used to enhance the heat transfer rate in many applications of heat transfer. The Reynolds number is the dimensionless number used to characterize the flow of the nanofluid to enhance the heat transfer rate. The current study, the effects of Reynolds number on 0.01% volume concentrations of the aluminium oxide (Al2O3) nanoparticles in the ethylene glycol through the flow in the pipe are investigated. In the study, ethylene glycol is considered as the base fluid. The thermophysical characteristics of the Al2O3/EG nanofluid were determined in the current work using a cylindrical copper pipe with an 8 mm diameter and 400 mm length. The heat transfer coefficient (HTC) and Nusselt number were calculated for the Reynolds number varied from 200 to 1200, considering nanofluid inlet temperature of 298 K and constant heat flux at the wall surface of pipe 1100 W/m2 K. The findings showed that the HTC and Nusselt number of the nanofluid flow in the pipe increased as the Reynolds number increased. Further, an exponential correlation was proposed for variation of the Reynolds number with HTC and Nusselt number for the obtained results. ANSYS Fluent software was used for the analysis of the nanofluid flow though pipe.

Efficiency improvement of ternary nanofluid within a solar photovoltaic unit combined with thermoelectric considering environmental analysis

Impacts of environmental parameters and dust deposition on the efficiency of solar panel have been scrutinized in this article. To gain thermal output, trapezoidal cooling channel has been attached in the bottom of the panel incorporating ternary nanofluid. To produce working fluid, water has been mixed with Fe3O4TiO2GO nanoparticles. Also, the arrangement of fins has been considered to grow the cooling rate of the silicon layer. The existence of a thermoelectric layer above the cooling channel leads to higher electrical output. Efficacy of ambient temperature (Ta), speed of wind (Vwind) and inlet temperature (Tin) and velocity (Vin) of ternary nanofluid on performance of PVT has been assessed. As Tin increases, electrical efficiency declines about 3.63%. Increase of ambient temperature makes thermal performance enhance about 33.46%. The PVT efficiency decreases about 13.14% and 16.6% with augment of wind speed and dust deposition. CO2 mitigation has been uced about 15.49% in presence of dust while it increases about 17.38% with growth of ambient temperature.

Heat transfer performance of an automotive radiator with MWCNT nanofluid cooling in a high operating temperature range

• An update review on nanofluids in an automotive radiator is presented. • Evaluation of the nanofluid stability using the UV–vis spectrophotometric method. • Thermophysical properties of MWCNT water/EG nanofluids are experimentally investigated. • Thermal performance of MWCNT nanofluids in a temperature range of 80–105 °C. • Observed agglomeration and sedimentation after experimental test in high temperature. This study investigates the heat transfer performance of multiwalled carbon nanotube nanoparticles (MWCNT) dispersed in a binary mixture of water-EG (ethylene glycol) at a volumetric ratio of 50:50 in an automotive radiator. The nanofluids were prepared using the two-step synthesis method at volumetric ratios of 0.025%, 0.05% and 0.1%. The UV–vis spectrophotometry method was used to evaluate the colloidal stability of the samples, reporting the absorbance-concentration relationship according to the Beer-Lambert law. Thermophysical properties such as thermal conductivity and viscosity were measured experimentally and compared with correlations in the literature. The influence of nanoparticle concentration as well as the coolant inlet temperature, of up to 105 °C, on the heat transfer rate and in the overall heat transfer coefficient were evaluated experimentally. The air velocity was maintained constant at 2 m/s and the coolant mass flow rate ranged between 0.09 kg/s and 0.11 kg/s. The maximum increases for the heat transfer rate and for the overall heat transfer coefficient were 4.6% and 4.4%, respectively. The results show that the increase in the concentration of nanoparticles can improve the performance in heat transfer, although the performance decrease for high nanofluid inlet temperatures in the radiator was significant. Finally, the stability of the nanofluids was reassessed after performing tests on the radiator, demonstrating high aggregation and sedimentation of nanoparticles.

Thermodynamic and optical analyses of a novel solar CPVT system based on parabolic trough concentrator and nanofluid spectral filter

This study presents the design and performance evaluation of a novel concentration photovoltaic/thermal (PV/thermal) system based on parabolic trough concentrator and indium tin oxide-ethylene glycol (ITOEG) nanofluid spectral filter. The overall design principle of the PV/thermal system is introduced, and the ITOEG nanofluid spectral filter is prepared and experimentally tested. For the full spectrum, the average transmittance and absorbance of the nanofluid spectral filter are 69.1% and 30.9%. The optical behaviour evaluation results reveal a double-peak radiation flux density distribution on the nanofluid channel bottom surface as well as on the solar cell module surface. When the north-south sun-tracking error increases to 0.2°, the optical efficiency of the PV/thermal system decreases to 93.7%. That means the system has a relatively good adaptability to the sun-tracking error. The thermodynamic analysis results reveal that the theoretical photoelectric conversion and solar thermal efficiencies of the PV/thermal system are 29.1% and 17.2%. The thermal efficiency of the PV/thermal system can be increased by increasing the nanofluid inlet flow velocity or by decreasing the nanofluid inlet temperature properly.

Simulation study of Al2O3-H2O nanofluids as radiator coolant using computational fluid dynamics method

The objective of this study was to investigate the influence of nanofluid concentration on the heat transfer rate of radiator pipes. This study used computational fluid dynamics simulation method of ANSYS Fluid Flow Fluent software. The working fluid used in this study was nanofluid prepared of Al2O3 and H2O mixture. Simulation was performed at various Al2O3 nanoparticles concentration ranging from 0 to 1%. The velocity and inlet temperature of nanofluid were set at 0.4 m/s and 130°C, respectively. The results of the simulation showed that the heat transfer rate and outlet temperature of nanofluid were influenced by the nanoparticles concentration. The rate of heat transfer increased with the increased of nanoparticles concentration. Among the tested concentration, 1% Al2O3 provided better heat transfer activity in which it is capable to reduce the high inlet fluid temperature to become about 80°C, very close to the recommended working conditions.

Development of a mathematical model for prediction of heat transfer coefficient in micro-channel heat sink

The advancement of miniaturization and high-density manufacturing of electronic devices necessitates lightweight and high-performance heat dissipation components. As a result, traditional coolants and cooling technologies are rapidly unable to satisfy the ever conditioning problems and requirements of specific high temperature generated electronic devices. A microchannel heat sink (MCHS) has been extensively researched and commonly used in electronics cooling as a novel system that is highly suitable for applications with high power and small heat dissipation space. This research presents a mathematical model focused on dimension analysis to determine the heat transfer coefficient of a microchannel heat sink in electronics cooling. Buckingham Pi (π)theorem with dimensional analysis was used to determine a functional correlation between the heat transfer coefficient and independent variables. Independent variables comprise; thermal conductivity (copper MCHS), hydraulic diameter (MCHS), length (MCHS), a mass flow rate of nanofluid, the density of nanofluid, inlet temperature of nanofluid, heat flux, % by volume concentration of nanoparticle and thermal conductivity of nanofluid. The established relationship between dependent and independent variables concerning various operating conditions is helpful for analyzing behaviour.

A three-dimensional thermal analysis for cooling a square Light Emitting Diode by Multiwalled Carbon Nanotube-nanofluid-filled in a rectangular microchannel

The aim of this paper is to ensure proper thermal management in order to remove and dissipate the heat produced by a square Light Emitting Diode (LED), as well as to ensure stable and safe operation by reducing the junction temperature. For this, we developed a three-dimensional code, time-dependent that solves the systems of equations for the mass, momentum, and energy using Comsol Multiphysics. After validation of this numerical 3D code, the thermal performance of a LED cooling system with three nanofluids such as MWCNT-Water, MWCNT-Ethylene Glycol, and MWCNT-Engine oil is studied numerically into account of aggregation effect. Several parameters such as: the power of the LED lamp, the inlet temperature and velocity of nanofluid, the length of the heat sink, and the length of the microchannel have been varied in order to find an optimal condition allowing a good heat dissipation from the LED chip to the heat sink. It was concluded that the use of MWCNT-Water in the microchannel is the best nanofluid that can cool the heat sink. In addition, the increase of velocity inlet of the coolant in the microchannel, the length of the heat sink, and the microchannel length while the decrease of the inlet temperature of nanofluid in the microchannel are an important factors allowing the decrease of the junction temperature of the square LED lamp.

Experimental investigation of Al2O3-water nanofluid as a secondary fluid in a refrigeration system

In the present study, a new technique of utilizing nanofluid as a secondary fluid in a secondary loop of refrigeration system is examined. This secondary loop serves for providing cooling in specific applications such as walk-in coolers and freezers. The secondary loop is obtained across the evaporator section wherein the refrigerant R134a extracted heat from the nanofluid. The evaporator here is classified as shell and coil heat exchanger where nanofluid flowed in the shell side and refrigerant flowed in the coil. A compressor, expansion valve and water cooled condenser are the major integral parts of the system. Experiments were conducted for various volume concentrations of Al2O3 nanofluid (0-15%), mass flow rates (40-80 g/s) and nanofluid inlet temperatures (30-40 °C). The modified system exhibited superior performance when Al2O3 nanofluid was employed in the secondary loop as compared to base fluid (distilled water) while operating at the same mass flow rate and inlet temperature. A maximum COP of 6.5 was achieved for nanofluid inlet temperature 40 C at mass flow rate 80 g/s and volume concentration 15%. The enhancement in refrigeration effect and coefficient of performance is attributed to micro conduction effect due to the rise in thermal conductivity of nanofluid as compared to distilled water.

Thermal performance analysis of a 1–5 TEMA E shell and coil heat exchanger operating with SWCNT–water nanofluid with varied nanoparticle concentration

Single-walled carbon nanotube–water nanofluids were tested in a 1–5 TEMA E shell and coil heat exchanger. Cold nanofluid, flowing inside the coil, was heated by hot water flowing in the shell side. Volumetric fraction of nanoparticles, inlet temperature of nanofluid, and mass flow rate of nanofluids ranged from 0 to 0.21%, 2.3 to 23.4 °C, and 40 to 90 g/s, respectively. For a given Reynolds number, at the coil side, pure base fluid (φ = 0%) performed better than low-concentration nanofluid samples (φ = 0.035% and 0.053%) and was nearly equivalent to the nanofluid of highest concentration, φ = 0.21%. The thermal conductivity enhancement factor of the nanofluid ranged from 0 to 0.2 and to 0.45, at inlet temperatures of 30 °C and 50 °C, respectively. It is believed to work in favor of a better performance of the nanofluid samples. On the other hand, the unusual (literature-wise) low temperature of the nanofluid further amplified the enhancement of the nanofluid viscosity, with a reduction effect on the Reynolds number. Besides, other thermal resistances of the heat exchanger work toward an attenuation of the enhancement effect that nanoparticles may have in the heat exchanger performance.

Modeling and identification of combined effects of pulsating inlet temperature and use of hybrid nanofluid on the forced convection in phase change material filled cylinder

Effects of pulsating heat transfer fluid temperature and hybrid nano-additive inclusion in the base fluid are numerically studied for laminar forced convection through a phase change material embedded thermo-fluid system with finite element method. Effects of different values of Reynolds number (between 250 and 1000), amplitude (between 0 and 0.05) and frequency (Strouhal number between 0.01 and 0.5) of pulsating inlet temperature, nanoparticle volume fraction of hybrid particles (between 0 and 0.02) on the dynamic features of the system with performance characteristics are analyzed. It is observed that the phase change material onset temperature becomes oscillating with drastically reduction of full completion time as the Reynolds number and amplitude of pulsation are increased. The amount of reduction in the full phase transition is 63% when cases at Re=100 to Re=400 are compared. When lowest and highest amplitude configurations are compared, 62% reduction in the complete phase transition time is observed while the impact of frequency is marginal at higher frequencies. When the hybrid nanoparticles are introduced in the base fluid, transition time and dynamic features of onset temperatures are affected. Successful results that capture the dynamic behavior of the phase change embedded thermal system is achieved with a nonlinear dynamic system modeling approach.

Optimization on heat-transfer coefficient of plate heat exchanger using MWCNT-TiO2 nanofluid by response surface methodology

In this present study, MWCNT-TiO2 hybrid nanocomposite synthesized by solvothermal synthesis method with TiCl4 as a precursor. Then the hybrid nanocomposite based nanofluid produced using base fluid water/Ethylene-glycol (50:50). The microscopic techniques like SEM, TEM and XRD were used to characterize the morphological studies of synthesized MWCNT-TiO2. The heat-transfer coefficient of synthesized nanofluid inside the Plate Heat Exchanger (PHE) has experimented at selected levels of particle concentrations, inlet temperature and volume flow rate by RSM based Box-Behnken method. The findings revealed a more substantial linear effect at the heat-transfer coefficient of MWCNT-TiO2 hybrid nanofluid by chosen process parameters. ANOVA results showed that the heat-transfer coefficient of hybrid nanofluid considerably enhanced at a selected higher level of particle concentration and volume flow rate of the MWNCT-TiO2 hybrid nanofluid. At the same time, the heat-transfer coefficient decreased at a higher level of inlet temperature of MWNCT-TiO2 hybrid nanofluid. The optimization result compared with the confirmatory experiments, and it yielded less than 1% error which ensures a better agreement with the predicted results.

Thermal performance analysis of mechanical draft cooling tower filled with rotational splash type packing by using nanofluids

In this study, effects of using nanofluid (distilled water as base fluid and aluminum oxide and copper oxide as nanoparticles) on thermal performance of mechanical draft cooling tower have been experimentally investigated and results have been compared with performance of the tower in presence of pure water. A counter flow wet cooling tower with non-uniform and rotational splash type packing has been used. Experiments have been carried out to investigate the effects of inlet temperature of nanofluid, concentration and type of nanofluid, and mass flow ratio of working fluid to air (L/G) on the thermal performance of the cooling tower. Preparation of the nanofluid has been accomplished in two-step method, by adding sodium dodecyl benzenesulfonate surfactant to improve the dispersion of particles and stability of suspension. Present results show that by using nanofluid, thermal performance of the cooling tower improved, and this improvement varies depending on inlet temperature of nanofluid, type and concentration of nanofluid. For instance, with an increase in the inlet temperature of aluminum oxide/water nanofluid (0.1 wt%) from 37.5 to 42.5 °C, effectiveness of the tower increased by 11%. However, using pure water with the same conditions, the effectiveness increased about 8.5%. Furthermore, by increasing the concentration of this nanofluid from 0 to 0.15 wt%, the effectiveness increased about 7.2%. Finally, by using copper oxide/water nanofluid, performance of the cooling tower improved with effectiveness about 5%.

Improving hydrothermal performance of hybrid nanofluid in double tube heat exchanger using tapered wire coil turbulator

Tapered wire coil insert is proposed as a novel enhancer in the double tube heat exchanger and experimental studies on Al2O3 + MgO hybrid nanofluid flowing under the turbulent condition are performed to investigate the hydrothermal characteristics. Effects of using tapered wire coil turbulator and hybrid nanofluid on the hydrothermal behaviors are examined for different coil configurations (Converging (C) type, Diverging (D) type and Conversing-Diverging (C-D) type) and hybrid nanofluid inlet temperatures and volume flow rates. Results show that D-type wire coil insert promotes better hydrothermal performance as compared to C-type and C-D type. Nusselt number and friction factor of hybrid nanofluid using D-type, C-D type and C-type wire coil inserts enhance up to 84%, 71% and 47%, and 68%, 57% and 46%, respectively than that of water in tube without insert. The entropy generation of hybrid nanofluid is lower than that of base fluid in all cases. The thermal performance factor for hybrid nanofluid is found more than one with all inserts. The thermal performance factor is observed a maximum of 1.69 for D-type coil. The study reveals that the hybrid nanofluid and tapered wire coil combination is promising option for improving the hydrothermal characteristics of double pipe heat exchanger.

Improving hydrothermal performance of double-tube heat exchanger with modified twisted tape inserts using hybrid nanofluid

The experimental studies on Al2O3 + TiO2 hybrid nanofluid flowing under the turbulent condition in a double-tube heat exchanger with various modified V-cuts twisted tape inserts are performed to study the hydrothermal characteristics. The hybrid nanofluid is prepared with a volume concentration of 0.1% by dispersing Al2O3 and TiO2 nanoparticles by equal volume ratio in distilled water. The effect of using twisted tape turbulator (with and without V-cuts) and hybrid nanofluid on the heat transfer and pressure drop characteristics are evaluated for different twist ratios, V-cut depth ratios, V-cut width ratios and hybrid nanofluid inlet temperatures. Results show that Nusselt number as well as friction factor increases with the decrease in twisting ratio, increase in depth ratio, decrease in width ratio and decrease in nanofluid inlet temperature. Maximum improvements in 132% for Nusselt number and 55% for friction factor are obtained as compared to that for the water in the tube without twisted tape. The values of thermal performance factor and entropy generation ratio are greater than unity for hybrid nanofluid for all modified twisted tape inserts.

Multi-Response Optimization of Nanofluid-Based I. C. Engine Cooling System Using Fuzzy PIV Method

Effective cooling of the internal combustion (I. C.) engines is of utmost importance for their improved performance. Automotive heat exchangers used as radiator with low efficiency in the industry may pose a serious threat to the engines. Thus, thermal scientists and engineers are always looking for modern methods to boost the heat extraction from the engine. A novel idea of using nanofluids for engine cooling has been in the news for some time now, as they have huge potential because of better thermal properties, strength, compactness, etc. Nanofluids are expected to replace the conventional fluids such as ethylene glycol, propylene glycol, water etc. due to performance and environmental concerns. Overall performance of the engine cooling system depends on several input parameters and therefore they need to be optimised to achieve an optimum performance. This study is focussed on developing a nanofluid engine cooling system (NFECS) where Al2O3 nanoparticles mixed with ethylene glycol (EG) and water is used as nanofluid. Furthermore, it also explores the effect of four important input parameters of the NFECS i.e., nanofluid inlet temperature, engine load, nanofluid flow rate, and nanoparticle concentration on its five attributes (output responses) viz thermal conductivity of the nanofluid, heat transfer coefficient, viscosity of the nanofluid, engine pumping power required to pump the desired amount of the nanofluid, and stability of the nanofluid. Taguchi’s L18 orthogonal array is used as the design of experiment to collect experimental data. Weighting factors are determined for output responses using the Triangular fuzzy numbers (TFN) and optimal setting of the input parameters is obtained using a novel fuzzy proximity index value (FPIV) method.

Hydro-thermal behaviour determination and optimization of fully developed turbulent flow in horizontal concentric annulus with ethylene glycol and water mixture based Al2O3 nanofluids

In this study, a comprehensive analysis of forced convection heat transfer and pressure drop through a concentric annulus heated from the inner wall and utilizing ethylene glycol (EG)-water based nanofluids for fully developed turbulent flow are conducted. In this context, effects of Reynolds number (10000–100,000), annulus radius ratio (0.1–0.9), EG concentration (0%–60%), nanoparticle volume fraction (0%- 1.5%) and nanofluid inlet temperature (0 °C - 50 °C) on Nusselt Number and pumping power have been analysed. To obtain nanofluids thermophysical properties, experimental data is implemented. To calculate the Nusselt number and friction factor, generalized formulations obtained from the direct numerical simulation are used. It is concluded that the Nusselt number increases with increasing Reynolds number and EG concentration while decreases with increasing radius ratio and inlet temperature in all conditions. In most cases, as nanoparticle volume fraction increases, Nusselt number increases while there are some opposite conditions. Besides, it is determined that the pumping power increases with increasing Reynolds number, EG concentration, nanoparticle volume fraction and radius ratio and decreases with increasing nanofluid inlet temperature. In addition, Response Surface Methodology and desirability function approach is implemented to determine the optimum operating conditions by maximizing Nusselt Number and minimizing pumping power for different scenarios.

Measurement of Local Convective Heat Transfer Coefficient of Alumina-Water Nanofluids in a Double Tube Heat Exchanger

Heat transfer coefficient and thermal efficiency of γ-Al2O3/water nanofluids flowing through a double tube heat exchanger were experimentally investigated. The nanoparticles were well dispersed in distilled water at 0.05–0.15 %vol. A large number of experiments were performed at different fluid flow rates under turbulent flow regime (18,000<Re<40,000) and various nanofluid inlet temperatures ranging from 45 °C to 65 °C. The heat transfer coefficients were measured along the length of the heat exchanger. Results showed that the local heat transfer coefficients have an asymptotic behavior. Furthermore, the addition of these small amounts of nanoparticles to the base fluid augmented the heat transfer up to 16% at the best conditions. In the end, the thermal performance factor was calculated to find the optimum condition at which the nanofluid was used. It was shown that the thermal performance factor of this nanofluid could reach to 1.11. This value was obtained at the nanoparticle concentration of 0.15 vol.% and Reynolds number 18000