Thermal Analysis Of Engine Cylinder Fins By Varying Its Geometry And Material Mr. N. Phani Raja Rao, Mr. T. Vishnu Vardhan 1. M.Tech- CAD/CAM pursuing Student, Intell Engineering College, Ananthapuramu. 2. Associate Professor & HOD, Intell Engineering College, Ananthapuramu Abstract The Engine cylinder is one of the major automobile components, which is subjected to high temperature variations and thermal stresses. In order to cool the cylinder, fins are provided on the surface of the cylinder to increase the rate of heat transfer. By doing thermal analysis on the engine cylinder fins, it is helpful to know the heat dissipation inside the cylinder. The principle implemented in the project is to increase the heat dissipation rate by using the invisible working fluid, nothing but air. We know that, by increasing the surface area we can increase the heat dissipation rate, so designing such a large complex engine is very difficult. The main purpose of using these cooling fins is to cool the engine cylinder by air. The main aim of the project is to analyze the thermal properties by varying geometry, material and thickness of cylinder fins. Transient thermal analysis determines temperatures and other thermal quantities that vary over time. The variation of temperature distribution over time is of interest in many applications such as in cooling. The accurate thermal simulation could permit critical design parameters to be identified for improved life. Presently Material used for manufacturing cylinder fin body is Aluminum Alloy A204 which has thermal conductivity of 110-150W/mk. We are analyzing the cylinder fins using this material and also using Aluminum alloy 6061 and Magnesium alloy which have higher thermal conductivities. Keywords: Shape, Material and Geometry of the fin, Transient thermal analysis. 1. Introduction The internal combustion engine is an engine in which the combustion of a fuel (normally a fossil fuel) occurs with an oxidizer (usually air) in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and -pressure gases produced by combustion applies direct force to some component of the engine, such as pistons, turbine blades, or a nozzle. This force moves the component over a distance, generating useful mechanical energy. All the heat produced by the combustion of fuel in the engine cylinders is not converted into useful power at the crankshaft. A typical distribution for the fuel energy is given below:  Useful work at the crank shaft = 25 per cent  Loss to the cylinders walls = 30 per cent  Loss in exhaust gases = 35 per cent  Loss in friction = 10 per cent It is seen that the quantity of heat given to the cylinder walls is considerable and if this heat is not removed from the cylinders it would result in the pre- ignition of the charge. In addition, the lubricant would also burn away, thereby causing the seizing of the piston. Excess heating will also damage the cylinder material. Keeping the above factors in view, it is observed that suitable means must be provided to dissipate the excess heat from the cylinder walls, so as to maintain the temperature below certain limits. However, cooling beyond optimum limits is not desirable, because it decreases the overall efficiency due to the following reasons: 1. Thermal efficiency is decreased due to more loss of heat to the cylinder walls. 2. The vaporization of fuel is less; this results in fall of combustion efficiency. 3. Low temperatures increase the viscosity of lubrication and hence more piston friction is encountered, thus decreasing the mechanical efficiency. 404 International Journal of Engineering Research & Technology (IJERT) Vol. 2 Issue 8, August - 2013 ISSN: 2278-0181 www.ijert.org IJERTV2IS80201