National Conference On Recent Trends And Developments In Sustainable Green Technologies Journal of Chemical and Pharmaceutical Sciences www.jchps.com ISSN: 0974-2115 JCHPS Special Issue 7: 2015 NCRTDSGT 2015 Page 351 IMPROVING THE HEAT REMOVAL RATE USING NANO PARTICLE MIXED COOLANT IN RADIATOR S.P. Venkatesan * . Joshua Mathew, Jithin Alex Melel Department of Mechanical Engineering, Sathyabama University * Corresponding Author: Email: spvsathyabama@gmail.com ABSTRACT Performance of an engine is greatly dependent on the cooling system of the engine. Addition of nanoparticles to the coolant changes the physical and chemical properties of any coolant. Hence latent heat and thermal conductivity are improved. Quantity of coolant required for the radiator heat removal is hence decreased. Improving the thermal efficiency of the engine leads to decrease in concentration of emissions in the exhaust. Nanoparticles improve the cooling rate when they are used along with the coolant as base fluid in cooling systems. The rising demand for powerful and efficient engine calls for the use of a coolant with better heat transfer characteristics. Keywords: Automobile Radiator, Nanofluids, Thermal Conductivity, Heat Transfer Enhancement. INTRODUCTION Traditionally the dissipation of heat in the automobile engine is done using the radiator, cooled by coolants such as water or ethylene glycol. The research in the design of the radiator is almost saturated since several researchers have studied exhaustively the material, profile and design of the radiator fins. The nano fluids are suspensions of nano sized metallic or non-metallic oxide particles in a base fluid. These nano fluids exhibit good thermal properties when put to comparison with different fluids because they possess more surface area by virtue of existing in nano size. Further these nano fluids exhibits more inter particle/inter fluid - particles/fluid-particle- surface of flow passage, turbulence and mixing. Hence, the nano fluids are the promising material and technology for improving the efficiency of the automobile radiator and the optimization of its design. Various parameters influence the thermal conductivity of nanofluids, namely, volume fraction, material, size, shape of the nano particle, nature of base fluid and working temperature. The application of the nano fluids as coolant in automobile radiator appears to be promising, but it has its challenges namely high cost involved in the production of nano fluids, long term stability of nano fluids, etc. The van der Waals force among the nano particles affects the stability of the nano fluids. The van der Waals force causes the nano particles to form clusters and settle down, thus causing the nano fluids to lose their stability. The dispersion of the nano particles in the base fluid is ensured by sonication, homogenization and addition of surfactant which ensures the nano particles remain suspended in the nano fluid for long durations (Rashmi W et al., 2011). The base fluids, nanoparticles and additives are used in the preparation of nanofluid coolants (M Khalid et al., 2014). PROPERTIES OF NANO FLUIDS Yu et al., 2009 observed that by adding 5% of zinc dioxide nano particle to ethylene glycol, there was a 26.5% thermal conductivity increase. H.A. Mintsa, et al., 2009 studied the aqueous nano fluids made under copper oxide and alumina. They found that smaller particles influence a good thermal conductivity where the volume fraction has no effect. M. Eftekhar et al.,2013 prepared nano fluids under 170nm sized silicon carbide particle with 3.7% volume concentration at constant Reynolds number. They observed that the heat transfer was increased to about 50 – 60% in comparison to base fluid. Rahul.A.et al.,2013 studied the heat transfer in a radiator using Al2O3 and ethylene glycol added with water, found that the volume fraction and mass flow rate of the nano fluid influence the heat exchange in the radiator.. Singh et al., 2006 found that the application of nano fluids as coolant radiator can aid in the reduction of radiator size of up to 10% and a fuel say up to 5%. Pak B C et al.,1998 observed that 40% increase in thermal conductivity of the automobile engine was achieved by using a nano fluid contained ethylene glycol and 0.3% of copper particles. Y. Hwang et al., 2007 observed that the thermal conductivity of the base fluid and volume fraction of the nano particle greatly influences the thermal efficiency. Wilson CA et al., 2006 studied the stability studies on nano fluids with diamond nano particles with respect to time. Paresh Machhar et al., 2013, synthesized a nano fluid by dispersing TiO2 in water and observed it was stable for several days without sedimentation. EXPERIMENTAL SETUP Construction and working