Nano Fluids Research Papers - Academia.edu (original) (raw)

Shell and Tube heat exchangers are having special importance in boilers, oil coolers, condensers, pre heaters. Shell and Tube heat exchanger is one such heat exchanger, provides more area for heat transfer between two fluids in comparison with other type of heat exchanger. To intensify heat transfer with minimum pumping power innovative heat transfer fluids called Nano fluids have become the major area of research now a days.

- by
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- Mechanical Engineering, Heat Transfer, Nano Fluids, Shell and Tube Heat Exchanger

In transport phenomena, precise knowledge or estimation of fluids properties is necessary, for mass flow and heat transfer computations. Viscosity is one of the important properties which are affected by pressure and temperature. In the present work, based on statistical techniques for nonlinear regression analysis and correlation tests, we propose a novel equation modeling the relationship between the two parameters of viscosity Arrhenius-type equation, such as the energy (í µí°¸í µí±) and the preexponential factor (í µí°´í µí±). Then, we introduce a third parameter, the Arrhenius temperature (í µí± í µí°´), to enrich the model and the discussion. Empirical validations using 75 data sets of viscosity of pure solvents studied at different temperature ranges are provided from previous works in the literature and give excellent statistical correlations, thus allowing us to rewrite the Arrhenius equation using a single parameter instead of two. In addition, the suggested model is very beneficial for engineering data since it would permit estimating the missing parameter value, if a well-established estimate of the other parameter is readily available.

- by Fethi Bin Muhammad Belgacem
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- Supercritical fluids, Fluid Dynamics, Nano Fluids, Viscosity

The main goal of this paper is to compare single-and two-phase modelling approaches for forced convection flow of water/TiO 2 nanofluid. The considered geometry is a horizontal tube with constant wall heat flux boundary condition where flow regime is turbulent. Computational fluid dynamics (CFD) approach is utilized for heat transfer and flow field estimation of the single-phase and three different two-phase approaches, namely Volume of Fluid, Mixture and Eulerian models. Results are presented for Reynolds numbers ranging from 9000 to 21000, for different nanoparticle diameters ranging from 20 to 40 nm, and values of volume fractions ranging from 0 to 4 percentages. The obtained results show that the values of

In this paper, forced convective heat transfer in a water based nanofluid has experimentally been compared to that of pure water in an automobile radiator. Five different concentrations of nanofluids in the range of 0.1-1 vol. % have been prepared by the addition of TiO 2 nanoparticles into the water. The test liquid flows through the radiator consisted of 34 vertical tubes with elliptical cross section and air makes a cross flow inside the tube bank with constant speed. Liquid flow rate has been changed in the range of 90-120 l/min to have the fully turbulent regime. Results demonstrate that increasing the fluid circulating rate can improve the heat transfer performance. Meanwhile, application of nanofluid with low concentrations can enhance heat transfer efficiency up to 45% in comparison with pure water.

- by Dadi Juneyd
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- Mechanical Engineering, Nano Fluids, Nanofluid, Heat transfer coefficient

Backward facing step arrangement is a classical case for fluid dynamics and heat transfer research. It is well characterized and therefore, used for benchmarking. However, ongoing studies reveal that the geometry also provide advantages in industry, especially in combustion and burners. This work utilizes computational fluid dynamics to investigate a specific laminar back facing step flow heat transfer case. Aluminium oxide nano particles are considered as an additive to water base fluid, forming nanofluid with different volumetric concentrations. Laminar flow passes a back facing step and encounters three circular grooves at bottom surface. All surfaces are adiabatic except the grooves. Constant surface temperature applies to the grooves. According to the simulation results, a separation bubble after back facing step and a reattachment point occur. Grooves alter expected wake due to physical and thermal interference. Investigation parameters are nano-particle concentration and Reyn...

- by Ideen Sadrehaghighi
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- Nano Fluids, Heat transfer using Nano fluids

Heat exchangers are the equipments used to transfer the heat from one fluid to another which are at different temperatures. Different types of heat exchangers are extensively used in various industries to transfer the heat between cold and hot fluids. The key role of the heat exchanger is to transfer heat at maximum rate. Concentric tube heat exchanger has potential application such as heat recovery from engine cooling circuit, oil cooling, de superheating in refrigeration and air conditioning, dairy, and chemical industry, pharmaceutical industry, refinery, etc. In this paper concentric tube heat exchanger is designed and fabricated with inner pipe made of copper and outer pipe made of galvanized iron. The CuO nanoparticles of about30 nm diameter are used in the present study. Nanoparticles were dispersed in the base fluid to enhance the rate of heat transfer and overall heat transfer coefficient. The results shows that heat transfer rate and overall heat transfer coefficient of nano fluid is slightly higher than that of the base liquid at same mass flow rate .The heat transfer rate and overall heat transfer coefficient of nano fluid increases with the increase of the volume concentration of the CuO nano fluid .There is a wide scope on performance of heat exchanger and applications of nano fluid in the coming years.

The boundary-layer flow of a nano-fluid over a moving surface, is simulated, by solving the governing equations, using an efficient implicit finite difference scheme called the Keller’s box scheme. This scheme is second order accurate even on a non-uniformly spaced grid. Surface injection or suction is considered through appropriate boundary conditions. The effect of nano-particles is taken into account by incorporating the thermo-physical property models. The effect of wall injection or suction, as well as the moving surface velocity, affects the wall shear stress and heat transfer rates in a complex manner inducing flow separation in certain cases. These results are very useful in assessing the effectiveness of the use of different nano-fluids for practical engineering applications.

- by Shehna Sagaria
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- Computational Fluid Dynamics, Nano Fluids

Due to the biological risks of using conventional lubricants, vegetable oils have been considered nowadays. Besides, to improve the tribological properties of the vegetable oils in various applications like metal forming processes, nanoparticles have been used as additives. This research evaluated the lubrication performance of the Al2O3 and TiO2 nanoparticles dispersed in rapeseed oil during the parallel tubular channel angular pressing (PTCAP) process. The experimental PTCAP tests have been fulfilled for three lubrication conditions, and the comparison between the PTCAP processed tubes have been performed in terms of maximum forming force, surface roughness, and microhardness. The experimental results indicate that adding the mentioned nanoparticles has been caused to at least a 50% reduction in the maximum deformation load. Moreover, a remarkable decrement in the surface roughness of the formed tubes has been obtained.

- by Ramin Hashemi and +1
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- Metal Forming, Sheet Metal Forming, Mechanical Behavior Of Materials, Metal Forming (Engineering)

In our aim is enhancing the efficiency of industrial air conditioning system with nano particle to increase the coefficient of performance. Due to the increase in machine technology and there is a lot of new innovation of air conditioner and its components, to make sure the proper running of machinery system, air conditioner and its cooling system. In this work planned to build a chilled water air conditioning system (HVAC) to reduce the improper working of the air conditioner which required cooling. This chiller plant is play a major role in these works and its benefits. This chiller plant system can used in the required places and reduce the power consumption. To avoid the environmental issue the water is flowing through the inside the air conditioner system to make sure the cooling water temperature. Introducing a ZnO as the nano particle, this nano particle have a good thermal conductivity, the heat transfer of the chiller plant system increases when the use of nano particle. The system has been running for certain period and it can be in off state for a certain period of time after it reaches the temperature range, to reduce the power consumption and the maintenance of the chiller plant. Experimental result indicates the comparative performance of the chilled water air conditioning system with and without use of nano particle which increase the 22% C.O.P of the system. Keywords: Chilled water air conditioning system, Nanoparticle, Zinc oxide(ZnO), Refrigerant(R22), Chiller, Nano fluid, Coefficient Of Performance. I. INTRODUCTION As a result of the multiple applications of chilled water air conditioning systems especially in large zones designs, needs to more savings in energy resources which need unconventional creatively ideas to enhance the system performance with a reduction in consuming power. Poor thermal characteristics of traditional fluids such as water, oil, glycerine, ethylene glycol and other liquids give a challenge to there searchers to enhance its thermal properties to rapid the heat transfer rate per unit time. Nanotechnology is a revolution in the field of technology and was exploited for several applications in industry, medicine, and agriculture. Nanoparticles are produced by reduction its size to less than 100 nm which has a unique favourite property to be applied. Nano-metals are added to the conventional fluid to form what is called nanofluid. Nanofluids are embedded suspensions enclosing nanoparticles of less than 100 nm in traditional base fluids. Nanofluids offer higher thermofluid properties compared to traditional base fluids. Nanofluids gain higher thermal conductivity which enhances the performance of heat transfer equipment. The improvement of heat transfer by nanofluids could be compacting the design of heat exchangers and hence reduction in cost. Because of the air conditioners consume about 40-50% of the total electric power of the air-conditioned zones, it has become a fertile field in front of researchers to seek alternatives to reduce the consumed power rates. So, several studies have been exploited the nanofluid significant thermal effect due to their energy efficiency in the engineering applications. Nanoparticles can be utilized in an expansive scope of improving the HVAC systems performance because of their improved both heat transfer rate and energy efficiency. The present investigation is concerned to study the performance characteristics of the vapour compression refrigeration cycle associated with a chilled water air conditioning system using nanofluid. The influence of nanofluid concentration ratio, nanoparticle type and nanofluid volumetric flow rate on the performance characteristics are discussed with comparing to pure water as the working fluid of a chilled water air conditioning system. The hybridization is improving the thermofluid properties that strongly depended on the mixture ratios and consequently changes in other physical properties. This emphasizes the importance of studying the performance characteristics of the vapor compression refrigeration cycle integrated with a chilled water system in the case of pure water, nanofluid. From this point, the current work examines the effect of the concentration ratio of nanomaterials on the performance of an air conditioning system associated with a chilled water system.

- by IJRASET Publication
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- Nanoparticles, Nano Fluids, Chiller, Coefficient of Performance

Nanofluids are quasi single phase medium containing stable colloidal dispersion of
ultrafine or nanometric metallic or ceramic particles in a given fluid. Nanofluids possess
immense potential of application to improve heat transfer and energy efficiency in several areas
including vehicular cooling in transportation, power generation, defense, nuclear, space,
microelectronics and biomedical devices. In the present contribution, a brief overview has been
presented to provide an update on the historical evolution of this concept, possible synthesis
routes, level of improvements reported, theoretical understanding of the possible mechanism of
heat conduction by nanofluid and scopes of application. According to this review, the future
developments of these technologies are discussed. In order to put the nanofluid heat transfer
technologies into practice, fundamental studies are greatly needed to understand the physical
mechanisms.

- by DURAIRAJAN A
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- Nano Fluids, Nano Technology, Thermal Conductivity

Solar radiance reaching Earth is plentiful and can be harnessed to provide electricity through solar PV panels. The main focus of this project is to analyse the temperature distribution on non-concentrating PV module with and without cooling and its effect on efficiency of PV panel. The efficiency of the PV panel is inversely proportional to its temperature. Current research is discussed and limited to two areas. The first is developing an accurate thermal model for solar panels. The second is on mechanisms that decrease the temperature of the cells. Cooling of photovoltaic cells is one of the main concerns when designing PV panel. Cells may experience both short-term (efficiency loss) and long-term (irreversible damage) degradation due to excess temperatures. The Active type of cooling a PV panel the rear surface of the panel is investigated. Forced convection through the copper tubes is assumed. Nano fluids have unique features different from conventional solid-liquid mixtures in which mm or μm sized particles of metals and non-metals are dispersed. Due to their excellent characteristics, Nano fluids find wide applications in enhancing heat transfer. Temperature of the PV panel and its Efficiency is found to vary with (H 2 O, ZnO and Al 2 O 3) and without cooling.

- by IJRASET Publication
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- Nano Fluids

Nano liquids are primarily used as coolants for their advanced heat properties in heat exchangers such as Electronic cooling systems (Like flat plates) and radiators. Heat transfer on a flat plate has been analyzed by several researchers. The nanofluid is prepared by suspending small nanoparticles in basic Water and ethylene glycol Such as fluids with or without stabilization techniques. The average size of nanoparticles is less than 100 nm, and The nanoparticles used in nano liquids are usually. The base fluid is a Well stimulant treatment fluid used in cosmetics Continuous phase fluid. Continuous phase fluid may be added, But it is not defined as water, and whether it is liquid or hydrocarbon May be without hydrocarbon gas. Well-induced therapy More than one base fluid can be used. The atomic number can Derived from the dimensional analysis of the Fourier law, because it is equal to the dimensionless temperature gradient at the surface: q Heat transfer rate, k is the constant heat. Conductivity and T is the temperature of the liquid. Sodium benzoic sulfate (SDBS) Water is used as a surfactant in the preparation of nano liquids. Cu nanoparticles with demonized water Nano-liquid samples of three-volume fractions are prepared; the average diameter of the nanoparticles is 25 nm. Many researchers have called the validity stability of nanofluids. The scattering behavior of various non-substances in the solvent varies and depends on many factors. A complete understanding of particleparticle-particle interaction to create a stable fluid. Electronics heat management and increasing the efficiency of fluids for transfer from air to liquid cooling systems. Improving the energy efficiency of electronic systems. Improving rack density for computer systems by reducing computers to sub-1U operating systems. Improvement in Power Module Life (MTPF). A nanofluid is a liquid containing particles the size of nanometers. The Nano liquids are obtained by scattering. Non-aqueous fluid (NAF) is a water-based permeable fluid. Commonly used NAF systems are reverse emulsions based on diesel oil, mineral oil or synthetic fluid. In NAF systems, the water level is emulsified in a continuous oil phase, also known as water-in-oil emulsion or reverse emulsion. Nusselt A is the number Is the dimensionless number closest to the pocket number. Both numbers are held inside the fluid Will be converted to a liquid with thermal energy Used to describe the ratio of thermal energy.

- by Sowmiya Soundharaj and +2
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- Nano Fluids

- by Eyüb CANLI
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- Fluid Mechanics, Heat Transfer, Nano Fluids, Heat transfer using Nano fluids

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide the excellent thermal performance in helical coil heat exchangers. Research studies on heat transfer enhancement have gained serious momentum during recent years and have been proposed many techniques by different research groups [1]. A fluid with higher thermal conductivity has been developed to increase the efficiency of heat exchangers. The dispersion of 1-100nm sized solid nanoparticles in the traditional heat transfer fluids, termed as nanofluids, exhibit substantial higher convective heat transfer than that of traditional heat transfer fluids. Nanofluid is a heat transfer fluid which is the combination of nanoparticles and base fluid that can improve the performance of heat exchanger systems. In this present paper the efforts are made to understand that how to compare the heat transfer rate in Copper helically coiled tube and squared coiled tube heat exchanger using Zinc Oxide and Titanium Dioxide Nano fluid by studying research papers of various authors.

- by IJRASET Publication
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- Nano Fluids, Heat transfer using Nano fluids, Helical Coil

- by Ali Beskok
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- Engineering, Mechanical Engineering, Applied Mathematics, Water

There are many aspects of the current day technology where the structures are subjected to many kinds of loads. Some of them are wind loads, and some of them are static loads, static loads occur when the physical load like weight or force applied in many cases like beams and structures. But the wind loads occur as the object is resting at the location and the wind is flowing around it. In this paper, such kind of condition taken for the solar panel and the solar farm where the single panel array subjected to higher and lower velocities of wind speeds. In this project, a solar panel array mounted at the ground plane is subject to wind speeds for 5mls and 25 m/s to investigate pressure effect on each panel in the array where the panel is placed at 180 to ground plane and 720 to the latitude. The design and simulation of this problem are done using commercial CFD package fluent, a subsidiary of Ansys Inc. The work presented in the paper is done using simulation concepts of computational fluid dynamics. This work helps in getting the overview and optimization of the necessary parts and areas that are affecting by the wind, which can predict the dislocations of the solar panels.

In this paper we report on combined Dufour and Soret effects on the heat and mass transfer in a Casson nanofluid flow over an unsteady stretching sheet with thermal radiation and heat generation. The effects of partial slip on the velocity at the boundary, convective thermal boundary condition, Brownian and thermophoresis diffusion coefficients on the concentration boundary condition are investigated. The model equations are solved using the spectral relaxation method. The results indicate that the fluid flow, temperature and concentration profiles are significantly influenced by the fluid unsteadiness, the Casson parameter, magnetic parameter and the velocity slip. The effect of increasing the Casson parameter is to suppress the velocity and temperature growth. An increase in the Dufour parameter reduces the flow temperature, while an increase in the value of the Soret parameter causes increase in the

- by Dr Priya Mathur
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- Nano Fluids, Non-newtonian Fluid Mechanics

In this present study, the forced convective heat transfer performance of automobile radiator has been studied experimentally by using Nano fluid (CuO-Water) as a coolant for an automobile radiator.. Experimental works were conducted to investigate the effect of Copper-Oxide (CuO) nanoparticles volume concentration and the operating temperatures on the rate of Nano fluids heat transfer in a radiator heat Exchanger. CuO nanoparticles were mixed with the base fluid water and also Sodium Lauryl Sulphate (SLS) powder was added to enhance the mixing process and stabilize the dispersion of the Nano fluids. Experimental runs were conducted at varying operating temperatures which include that, CuO-water at different temperature such as 40℃, 50℃, 60℃, 70℃, 75℃, 78℃, 80℃, 83℃. Among the operating temperatures selected for study 80℃, gives the best performance in heat transfer and the convection heat transfer coefficient. The results of the current work generally indicate that Nano fluids have the potential to enhance the heat transfer of a compact heat exchanger. Results indicate that, best overall heat transfer coefficient for the radiator is obtained at a hot fluid inlet temperature of 80℃, and at a flow rate of 0.075kg/sec.

- by IJAET Journal
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- Nano Fluids, Automotive Radiator Design, Heat Exchangers, CuO Nanowires

""We conducted non-equilibrium molecular dynamics simulations to investigate Kapitza length at solid/liquid interfaces under the effects of bulk liquid pressures. Gold and silicon were utilized as
hydrophilic and hydrophobic solid walls with different wetting surface behaviors, while the number of confined liquid water molecules was adjusted to obtain different pressures inside the channels. The interactions of solid/liquid couples were reparameterized accurately by measuring the water contact
angle of solid substrates. In this paper, we present a thorough analysis of the structure, normal stress, and temperature distribution of liquid water to elucidate thermal energy transport across interfaces. Our results demonstrate excellent agreement between the pressures of liquid water in nano-channels and published thermodynamics data. The pressures measured as normal stress components were characterized using a long cut-off distance reinforced by a long-range van der Waals tail correction term. To clarify the effects of bulk liquid pressures on water structure at hydrophilic and hydrophobic solid surfaces, we defined solid/liquid interface spacing as the distance between the surface and the peak value of the first water density layer. Near the gold surface, we found that interface spacing and peak value of first water density layer were constant and did not depend on bulk liquid pressure; near the silicon surface, those values depended directly upon bulk liquid. Our results reveal that the pressure dependence of Kapitza length strongly depends on the wettability of the solid surface. In the case of the hydrophilic gold surface, Kapitza length was stable despite increasing bulk liquid pressure, while it varied significantly at the hydrophobic silicon surface."
http://dx.doi.org/10.1063/1.4851395"

- by Murat Barisik
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- Water, Molecular Dynamics Simulation, Heat Transfer, Nanoscale heat transfer

Molecular dynamics (MD) simulations of heat transport through a water–silicon system are performed to investigate the thermal resistance at water/silicon interface. Interaction strength between water and silicon is varied in order to understand its effects while the proper strength value is characterized by matching the nano-scale contact angle value with the micro-scale experimental measurements through a water droplet study. Depending on surface wettability, different water distributions are developed near the surface, creating different couplings between water and silicon molecules for phonon transport. In addition, near surface water density is found to be dependent on the surface temperature for high wetting cases that closer packing of water molecules is observed near the cold surface. Interface thermal resistance values measured as Kapitza length (LK) showed strong dependence on water density structure formed next to the surface. Hence, variation of LK with temperature is not only measured due to the temperature dependence of phonon transport, but also due to the variation of near surface density with temperature. For studied water/silicon system (slightly hydrophobic with contact angle of 88°), density is independent of surface temperature, and LK decreases with increased temperature similar to the theoretical phonon transport predictions. MD predicted LK values (≈9 nm) are found to be consistent with experimental measurements.

- by Murat Barisik
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- Water, Molecular Dynamics Simulation, Heat Transfer, Silicon

The boundary-layer flow of a nano-fluid over a moving surface is simulated, by solving the governing equations, using an efficient implicit finite difference scheme called the Keller’s box scheme. This scheme is second order accurate even on a non-uniformly spaced grid. Surface injection or suction is considered through appropriate boundary conditions. The effect of nano-particles is taken into account by incorporating the thermo-physical property models. The effect of wall injection or suction, as well as the moving surface velocity, affects the wall shear stress and heat transfer rates in a complex manner inducing flow separation in certain cases. These results are very useful in assessing the effectiveness of the use of different nano-fluids for practical engineering applications.

- by Raman Balu and +1
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- Computational Fluid Dynamics, Nano Fluids
- by Ali Beskok
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- Engineering, Mechanical Engineering, Applied Mathematics, Water

Ample literature is available on design of solar systems. However the energy conversion efficiency is about 10%. Nearly 80% of the incoming solar energy is either reflected or absorbed as heat energy. It is expected that the efficiency of conversion is improved by using Nano-fluids in the flat plate solar collector system. An attempt is made in this paper to fabricate and to study the effect of different nano particle concentrations in water as base fluid. Nano particles of TiO2 are tried. Different particle concentrations ratios were chosen for testing. It has been observed that the thermal efficiency of solar flat plate collector has been improved by 30% using nano fluids in the water base fluid. The major contribution of the present work is to design and analyze the effect of adding the nano particles in the water base on the thermal efficiency of the solar water heaters. It has been observed that there is nearly 30% rise in the efficiency of the solar flat plate water heaters by using nano Particles.

- by IAEME Publication
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- Design, Manufacturing, Nano Fluids, Thermal Efficiency

Ample literature is available on design of solar systems. However the energy conversion efficiency is about 10%. Nearly 80% of the incoming solar energy is either reflected or absorbed as heat energy. It is expected that the efficiency of conversion is improved by using Nano-fluids in the flat plate solar collector system. An attempt is made in this paper to fabricate and to study the effect of different nano particle concentrations in water as base fluid. Nano particles of TiO 2 are tried. Different particle concentrations ratios were chosen for testing. It has been observed that the thermal efficiency of solar flat plate collector has been improved by 30% using nano fluids in the water base fluid. The major contribution of the present work is to design and analyze the effect of adding the nano particles in the water base on the thermal efficiency of the solar water heaters. It has been observed that there is nearly 30% rise in the efficiency of the solar flat plate water heaters by using nano Particles.

- by IAEME Publication
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- Nano Fluids, Solar Systems, Heat Energy, Thermal Efficiency
- by Seyyed Arash Mousavi
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- Nanotechnology, Nano Fluids, Nanoscience, Heat transfer using Nano fluids