IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________________ Volume: 05 Issue: 10 | Oct-2016, Available @ http://ijret.esatjournals.org 229 DESIGN AND STUDY THE EFFECTIVENESS OF ENGINE CYLINDER FIN WITH VARIABLE GEOMETRY AND MATERIAL N.Srinivasa Rao 1 , G.V. Subhash 2 , K. Ashok Kumar 3 , B.N. Malleswara Rao 4 1 Assistant.Professor, Mechanical Department, Shri Vishnu Engineering College for women, A.P, India 2 Assistant.Professor, Mechanical Department, Shri Vishnu Engineering College for women, A.P, India 3 Assistant.Professor, Mechanical Department, Shri Vishnu Engineering College for women, A.P, India 4 Assistant.Professor, Mechanical Department, Shri Vishnu Engineering College for women, A.P, India Abstract In automobiles, the engine cylinder is subjected to high temperature variations and thermal stresses .So as to cool the engine cylinder, fins are mounted on the engine cylinder to increase the rate of heat transfer. By doing thermal analysis on the engine cylinder fins you can know the rate of heat transfer inside the cylinder. The main objective of the project is to analyze the thermal behavior of cylinder fins by varying geometries, materials and thickness. In this project 2.5 mm and 3mm thickness of fins are considered for various fin geometries and they are designed using AUTO CAD 2016.Thermal analysis on the fins is done by using ANSYS WORKBENCH. In our project we have taken materials aluminum alloy 6063 and aluminum alloy 7068 instead of general material aluminum alloy 204. The geometries circular, rectangular and trapezoidal fins with Aluminum alloy 204, Aluminum alloys 6063 and 7068 of thickness 2.5mm &3mm are compared on the basis of total rate of heat flux & effectiveness. It is found that aluminum alloy 6063 of circular geometry with 2.5 mm thickness is having more rate of heat flux &effectiveness. Keywords: Aluminum alloys 6063, Aluminum alloys 7068, Aluminum alloy 204, ANSYS WORKBENCH, AUTO CAD 2016. --------------------------------------------------------------------***--------------------------------------------------------------------- 1. INTRODUCTION The term extended surface is commonly used in reference to a solid that experiences energy transfer by conduction and convection between its boundary and surroundings, a temperature gradient in x direction sustains heat transfer by conduction internally at the same time, there is heat dissipation by convection into an ambient at T ∞ from its surface at temperature T S , given as Q = h As (T S -T ∞ ) Where h=convection heat transfer coefficient A S =Heat transfer area of a surface When the temperatures T S and T ∞ are fixed by design considerations, there are only two ways to increase the heat transfer rate:(i) to increase the convection coefficient h, (ii) to increase the surface area A. in this situations, in which an increase in h is not practical or economical, because increasing h may require the installation of pump or fan or replacing existing one with larger one, the heat transfer rate can be increased by increasing the surface area. For heat transfer from a hot liquid to a gas, through a wall, the value of heat transfer coeffient on the gas side is usually very less compared to that liquid side (h gas <<<<h liquid ) .to compensate low heat transfer coefficient, the surface area on the gas side may be extended for a given temperature difference between surface and its surroundings. These extended surfaces are called fins. The fins are normally thin strips of highly conducting metals such as aluminium, copper, brass etc. The fins enhance the heat transfer rate from a surface by exposing larger surface area to convection. The fins are used on the surface where the heat transfer Coefficient is very low. Total heat produced by the combustion of charge in the engine cylinder may not convert into useful power at the crankshaft. so loss of heat approximately at the cylinder walls is 30% due to cooling. If this heat is not removed from the cylinders it would result in the preignition of the charge and also damage the cylinder material. as well as the lubricant may also burn away, so that causing the piston may seizing keeping the above factor in view , it is observed that suitable heat must be maintained in the cylinder. So that excess heat removed by adding the fins to the cylinder walls. 1.1 Classification of Fins Based on the geometry of fins. Fins can be classified into three type .They are 1. Longitudinal fins 2. Annular fins 3. Pin- fin or spine fins Longitudinal fins: It is a straight rectangular fin attached to a plane wall. It may be of uniform cross-sectional area, or its area may vary along its length to form a triangular, parabolic or trapezoidal shape.