Heat Transfer Enhancement in Automobile Radiator using Nanofluids: A Review Nikhil S Shrikhande 1* Student, IV semester M. Tech (Heat power engineering) V. M. Kriplani 2 Professor 1*, 2 Mechanical Engineering Department, G. H. Raisoni College of Engineering, Nagpur.440016 (India) 1*Corresponding author Abstract - In the development of the many modern technology the primary challenge is thermal management. If we are looking towards the automobile sector the thermal management is the most difficult challenge. Nanofluids are suspension of metallic or nonmetallic nanoparticles in the base fluid; it can be used to increase the heat transfer rate of various applications such as internal cooling system of gas turbine blades, cooling system for automobile engine. This paper contains the literature survey which gives the techniques to implementation of the nanofluids in the car radiator for the cooling of engine. Keywords: Heat transfer enhancement, passive method, Nanofluids, Al 2 O 3 , Car radiator. INTRODUCTION: High performance cooling is one of the important needs of many industries. Heat transfer flow fluid such as water, engine oil, ethylene glycol though they play important role in thermal management in industries they have poor heat transfer properties compared with those of most solid and are primary hindrends are of the high compactness and effectiveness of heat exchanger, extended surface, mini channel, micro channel etc. are use to enhance the cooling or heating rates but further enhancement is always in demand. Solid particles possess higher thermal conductivity. Nanofluids is a fluid having non sized solid particles, normally particle size less than 100 nm, disperse in the convectional based fluid water, mineral oil, ethylene glycol. This tremendously enhance the heat transfer characteristics (and little penalty in pressure drop) of original fluid. This is because of solid non particles these fluids have thermal conductivities several times higher than that of convectional fluid, several types of non particles can be employed for non fluid preparation, including metals such as gold, copper and silver. And also metal oxides such as Al 2 O 3 , CuO, TiO 2 , Fe 2 O 4 metals oxide are more attractive for heat transfer enhancement applications because of significantly lower cost compared to metals. Nanofluids are potentially applicable as alternative cooling for many areas such as electronics, air conditioning, automotives, power generation and nuclear application. DIFFERENT METHODS OF HEAT TRANSFER ENHANCEMENT: Active method: This method involves some external power input for the enhancement of heat transfer; some examples of active methods include induced pulsation by cams and reciprocating plungers, the use of a magnetic field to disturb the seeded light particles in a flowing stream, etc. Passive method: Passive heat transfer augmentation methods as stated earlier does not need any external power input. In the convective heat transfer one of the ways to enhance heat transfer rate is to increase the effective surface area and residence time of the heat transfer fluids. The passive methods are based on the same principle. Use of this technique causes the swirl in the bulk of the fluids and disturbs the actual boundary layer so as to increase effective surface area, residence time and consequently heat transfer coefficient in existing system. Following Methods are generally used, 1. Inserts 2. Extended surface 3. Surface modifications 4. Use of additives. ADDITIVES The additives include liquid droplet or solid particles, soluble trace additives and gas bubbles in single phase flows and trace additives which usually depress the surface tension of the liquid boiling system. Additives refers to a substance used to improve the performance of anything, like additives in fuel for better combustion, additives in water like ethylene glycol for increasing the heat transfer coefficient. There are different types of additives but we only discuss with nano particles. The nano particles are the particles having the diameter below the 100nm. Nanofluids are prepared by dispersing nanometer-sized particles, generally less than 100 nm, in a base fluid such as water, 174 Vol. 3 Issue 3, March - 2014 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 www.ijert.org IJERTV3IS030433