International Engineering Research Journal Enhancement of Heat Transfer Rate by Use of Nano Fluid in Radiator of Automobile

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1 International Engineering Research Journal Enhancement of Heat Transfer Rate by Use of Nano Fluid in Radiator of Automobile Ashwin Hukkeri 1,Prof.S. S. Ghorpade 2 1 Mechanical Engineering Department. Pune University, Sinhgad Academy of Engineering Kondhwa Pune, India. 2 Mechanical Engineering Department. Pune University, Sinhgad Academy of Engineering Kondhwa Pune, India. Abstract The objective of this numerical study is to discuss the thermal performance of car radiator using Al2O3 Nano fluid in temperature with 92 C. In this study, the heat transfer with water based Nano-fluids was numerically compared to that of pure water as coolant in an automobile radiator. The size of nanoparticle used was 100 nm. 2.5 lpm Liquid flow rate has been taken in CFD analysis and air velocity is 16.67m/s. The fluid inlet temperature was 92 C is given to find the optimum heat transfer rate. This paper deals with CFD simulation of an existing radiator in ANSYS FLUENT. The modelled in done in SOLIDWORKS 14 and then analyzed for heat transfer rate. The radiator was analyzed with Nano fluid (Al2O3) then and reanalyzed for the same. Keywords:Nanofluid, Heat transfer rate, Ansys Fluent, Solidworks Introduction Modern car engines generate a huge amount of heat. This heat is created when the fuel and air mixture is ignited in the combustion chamber. This explosion causes the piston to be forced down inside the engine, moving the connecting rods, and turning the crankshaft to create a power. Metal temperatures around the combustion chamber can exceed 550 C. In order to prevent the overheating of the engine oil, cylinder walls, pistons, valves, and other components by these extreme temperatures, it is necessary to effectively dispose of the heat. Approximately 33% of the heat in combustion is converted into power to drive the vehicle and its accessories. Another 33% of the heat is carried off into the atmosphere through the exhaust system. The remaining 34% must be removed from the engine by the cooling system. The nanofluid has the potential to improve the engine cooling rates as compare with water-cooling. These improvements can be used to remove engine heat with a reduced size cooling system. Smaller cooling system leads to use of smaller and lighter radiators which in turn will lead to better performance and increased efficiency. Alternatively, improved cooling rates can be used to remove more heat from higher horsepower engines with same size of cooling system. V.L.Bhimani et.al. [1] experimentally investigated forced convective heat transfer in a water based nanofluid. Five different concentrations of nanofluids in the range of vol. % have been used with flow rate in the range of lit./min. The result shows that heat transfer enhancement of 40-45% compared to pure water at the concentration of 1% vol. Gaurav Sharma et al. [2] Experimentally investigated the thermal conductivity and viscosity of Al2O3-engine nano-coolant. For 0.5% vol. concentration of Al2O3 nanofluid at 40ºC The maximum improved thermal conductivity is 5.7% and the enhancement in viscosity is 124%. Adnan M. Hussein et al. [3] experimentally investigated the friction factor and forced convection heat transfer enhancement using SiO2 nanoparticles suspended into water. Four different concentrations of nanofluids in the range of 1 to 4 % (Vol.) with changed flow rate from 1 to 5 lpm have been used. The maximum value of friction factor was increased to 22% and a highest value of the heat transfer coefficient enhances upto 40% for SiO2 nanoparticles with 4% volume concentration. Rahul A.Bhogare et.al. [4] illustrated a review on application and challenges of nano-fluids as coolant in automobile radiator. Nanofluids have great potential to improve automotive and heavy duty engine cooling rates by increasing the efficiency, lowering the weight and reducing the complexity of thermal management Chavan D.K. et.al. [5] illustrated the study, analysis and design of automobile radiator proposed with CAD drawing and geometrical model of the fan. He investigated that velocity increases with the increase in rpm of radiator fan. So he concluded that for optimum efficiency eliminates corners and develop radiator of circular shape. Deepak Chintakayalaet. al. [6] studied the cooling effect by using a nanofluid as a coolant in a radiator and is analyzed for evaluating the fluid flow and heat transfer characteristics. This study is analyzed by using a CFD software FLUENT. It is clearly observed that loss in temperature for conventional coolant is 17 C and for

2 nanofluid as coolant it is 20ºC. From his study he concluded that the rate of heat transfer is better when nanofluid (Al2O3 + water ) is used as coolant than conventional coolant. Navid Bozorgan et.al.[7] numerically investigated the use of CuO - water nanofluid as a coolant in a radiator at Chevrolet suburban diesel engine with a given heat exchanger capacity. The results showed that for CuOwater nanofluid at 2 % volume concentration circulating through the flat tubes with Re while the automotive speed is 70 km/hr, the overall heat transfer coefficient and pumping power are approximately 10 % and 23.8 % more than that of base fluid for given conditions. 2.0 Radiator CAD Model The Computational Fluid Dynamics methodology used was the lattice Boltzmann method as implemented in the commercially available CFD software. Simulations were performed with full scale geometry and evaluated at 16.67m/s air velocity. The Lattice Boltzmann method was chosen to obtain consistency with previous study performed by authors as well as providing an efficient approach to simulate unsteady flow effects. Modeling is done in Solidworks 14.0 software with the following geometry dimensions: S. No. Table 2.1.Radiator Dimension Parameter 1 Inlet diameter 2 Outlet diameter 3 Length 4 Height 5 Thickness 6 Capacity Dimension 25 mm 20 mm 360 mm 410 mm 30 mm 1.5 lit Fig.2.1 CAD Geometry view 1 Fig.2.2 CAD Geometry view Nanofluid Properties The test fluids are water based nanofluids which comprise of water and small amount (1-5 vol. %) of gamma alumina nanoparticle. The mean grain size of this gamma alumina is 100 nm and some different properties are appeared in Table 1. There was no dispersant or stabilizer added to nanofluid. This is because of the way that the expansion of any specialists might change the liquid properties [15] and the authors were intrigued to simulate the easiest actual condition experienced in the car radiator. Moreover, making exceedingly turbulent stream condition in the radiator tubes and associating channels ensures the adjustment of the nanoparticle in water. The characteristics of water and Al2O3 nanoparticles at room temperature are summarized in Table Table 3.1: Nanoparticle characteristics

3 Purity 99% Grain size (nm) 60 nm Specific surface area (m2/g) 200 Silicon (Si) content (ppm) 3.5 Calcium (Ca) content (ppm) 1.6 Iron (Fe) content (ppm) 0.2 Cobalt (Co) content (ppm) 0.8 Table 3.2: Properties Comparison at room temperature Sr.No. Properties Al2O3 (nano particle) Water+Eth ylene Glycol 1 Density (Kg/m3) Specific heat (J/KgK) 3 Thermal conductivity (W/m-K) Viscosity (N-s/m The physical properties of Al2O3 Nano particles and water+ Ethylene Glycol are taken from [13]. The molecule concentration can be viewed as uniform all through the system; the effective physical properties of the mixtures concentrated on can be assessed utilizing some traditional formulas as generally utilized for two stage liquids. These relations have been utilized to foresee nanofluid physical properties like density, specific heat, viscosity and thermal conductivity at different temperatures and concentrations [14]. In this paper, the accompanying connections were utilized to compute these physical properties of nanofluid: "n" is empirical shape element given by n=3/ψ, and ψ is the molecule sphericity, characterized as the proportion of the surface range of a circle with volume equivalent to that of the molecule, to the surface territory of the molecule, and in this paper n thought to be 3. is volume division of the nanoparticle added to the water. The proportions of physical properties of the nanofluid to those of immaculate water as an element of Nanoparticle concentration. It is evident that the expansion of little measure of alumina nanoparticle can change pretty much all the physical properties of the base liquid. 4. Results and Discussions: In the present paper thermal performance of the radiator at constant air flow of 60Kmph and constant flow rate (2.5L/min) has been carried out. With increase in the volume fraction of Al2O3 particles dynamic viscosity of nanofluid has been increased. The overall heat transfer coefficient based on the air side increase in the volume concentration of Al2O3 particles in the base fluid. An overall heat transfer W can be achieved for Al2O3+mixture of water-eg nanofluid compared W for based fluid The CFD analysis of temperature variations of base fluid (water & EG), are show bellows, Fig.4.1 Temperature distribution for base fluid (water & EG) In the above equations, the subscripts "p", "w" and "nf" refer to the particles, water and nanofluid respectively.

4 Heat Transfer, Q W W Fig.4.2 Velocity profile The CFD analysis of temperature variations of Al2O3 nanoparticles mixing with base fluid (water & EG), are show bellows, Fig.4.3 Temperature distribution for nanofluid Fig.4.4 Velocity profile The calculated values of the inlet-outlet temperature, heat transfer and efficiency of the base fluid as well as nanofluid are tabulated in Table 4.1 Table 4.1 Base fluid vs Nanofluid Description Base fluid Nanofluid Inlet Temp 92 C 92 C Outlet Temp 42 C 82.6 C Air Temp 33 C 33 C From the obtained results the Heat transfer rate and efficiency of the nanofluid are high. The life time of Engine is also increases. 5. Conclusion Generally, contribution of radiator to an engine is considered when the efficiency of a radiator is good and constant. Currently, the temperature factor is dependent on the fluid used in the radiator. So modification of fluid in the radiator contributes to the engine cooling through efficient radiator action. In this numerical research work, the total heat transfer rate from an automotive radiator is determined using two working fluids: water and water based nanofluid (Al2O3) at concentrations 0.5% on volume basis. From the result work, the following conclusions were made. Rate of heat transfer is increased in car radiator by addition of 0.5% Al2O3 nano powder of 100nm size in pure water at constant coolant flow rate of 2.5lph and constant air flow rate of m/s References 1) V.L.Bhimani,.P.P.Rathon and A.S.Sorathiya, Experimental study of heat transfer enhancement using water based nanofluids as a new coolant for car radiators.ijetae Vol.3, Issue 6,June ) Gaurav Sharma and Lal Kundan, Experimental investigation into thermal conductivity and viscocity of Al2O3 based engine coolant.ijrmet Vol. 3, Issue 6,MayOct ) Adnan M.Hussein, R.A.Bakar, K.Kadirgama,G.L.Ming Heat transfer augmentation for the car radiator by using nanofluid.mre, ISBN: doi. 4) Rahul A.Bhogare and B.S.Kotahwale A review on applications and challenges of nanofluids as coolant in automobile radiator International journal of scientific and research publications, volume 3,Issue 8, August 2013, ISSN ) Chavan D.K. and Tasgaonkar G.S. Study Analysis and Design of Automobile Radiator Proposed with

5 Cad Drawing and Geometrical Model of the Fan IJMPERD ISSN , Vol 3, Issue 2, June 2013, ) Deepak Chintakayala and, Rajamanickam C.S. CFD analysis of fluid flow and heat transfer of an automotive radiator with nano fluid IEEE. 7) Navid Bozorgan, Komalagan Krishnakumar,Nariman Bozorgan Numerical study on applications of CuO nanofluid in Automotive Diesel Engine Radiator Modern mechanical engineering 2012, 2, ) Paresh Machhar and Falgun Adroja Heat transfer enhancement of automobile radiator with TiO2 and water nanofluid International journal of engineering research and technology, ISSN , vol 2 Issue 5 may ) Ravikanth S.Vajjha,Debendra K.Das, Praveen K Namburu Numerical study of fluid dynamic and heat transfer performance of Al2O3 and CuO nanofluids in the flat tubes of a radiator, International Journal of Heat and Fluid Flow 31 (2010) ) Qijun Yu, Anthony G. Straatman Brian Thompson Carbon-Foam finned tubes in air-water heat exchangers applied thermal engineering 26 (2006) ) Chad Harris, Kavin Kelly,Tao Wang,Andrew McCandles and Shariar Motakef Fabrication Modelling and Testing of Micro-Cross-Flow Heat Exchanger Journal of microelectromechanical system, vol-11, no-6 December 2002, IEEE. 12) B.C. Pak and I.Y. Cho, Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles, Experimental Heat Transfer 11 (1998) ) Rahul A. Bhogare, B.S. Kothawale e SSN: ,p-ISSN: XVolume 11, Issue Ver. V (May- Jun.014), PP ) S.M. Peyghambarzadeh, S.H. Hashemabadi, M. Seifi Jamnani, S.M. Hoseini 2011 Elsevier Ltd. All rights resered.doi: /j.applthermaleng