EFFECT OF HEAT TRANSFER IN A CYLINDRICAL FIN BODY BY VARYING ITS GEOMETRY & MATERIAL

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1 Volue 1 Issue 8 (Septeber 214) EFFECT OF HEAT TRANSFER IN A CYLINDRICAL FIN BODY BY VARYING ITS GEOMETRY & MATERIAL D. MERWIN RAJESH K. SURESH KUMAR PG Student ASSOSCIATE PROFESSOR Dept. of Mechanical Engineering Dept. of Mechanical Engineering K.S.R.M College of Engineering K.S.R.M College of Engineering Kadapa, Andhra Pradesh Kadapa, Andhra Pradesh Abstract - The Engine cylinder is one of the ajor autoobile coponents, which is subjected to high teperature variations and theral stresses. In order to cool the cylinder, fins are provided on the cylinder to increase the rate of heat transfer. By doing theral analysis on the engine cylinder fins, it is helpful to know the heat dissipation inside cylinder. The principle ipleented in this project is to increase the heat dissipation rate by using the invisible working fluid, is air. We know that, by increasing the surface area we can increase the heat dissipation rate, so designing such a large coplex engine is very difficult. The ain purpose of using these cooling fins is to cool the engine cylinder by any air. A paraetric odel of piston bore fins has been developed to predict the transient theral behavior. The paraetric odel is created in 3D odeling software Pro/Engineer. Theral analysis is done on the fins to deterine variation teperature distribution overtie. The analysis is done using ANSYS. Analysis is conducted by varying aterial.in this thesis, Presently Material used for anufacturing cylinder fin body is uinu loy 24 which has theral conductivity of 15W/k. In this thesis, it is replaced with uinu alloy 775, Magnesiu and berylliu Keywords: heat dissipation, theral gradient, nodal teperature, heat flux. I. Introduction A. Cooling Syste for I.C. Engines: Internal cobustion engines at best can transfor about 25 to 35 percentage of the cheical energy in the fuel in to echanical energy. About 35 percent of the heat generated is lost in to the surroundings of cobustion space, reainder being dissipated through exhaust and radiation fro the engine. The teperature of the burning gases in the engine cylinder is about 2 to 25 C. The engine coponents like cylinder head, cylinder wall piston and the valve absorb this heat. Necessity for Engine Cooling 1. Engine valves warp (twist) due to overheating. 2. Daage to the aterials of cylinder body and piston. 3. Lubricating oil decoposes to for guy and carbon particles.4 Theral stresses are set up in the engine parts and Causes distortion (twist or change shape ) and cracking of coponents. 5. Pre ignition occurs (i.e. ignition occurs before it is required to igniter due to the overheating of spark plug. 6. Reduces the strength of the aterials used for piston and piston rings. 7. Overheating also reduces the efficiency A typical distribution for the fuel energy is given below: Useful work at the crank shaft = 25 per cent Loss to the cylinders walls = 3 per cent Loss in exhaust gases = 35 per cent Loss in friction = 1 per cent Here we used air cooling syste in the engine which uses fins, it is a extended surface used to transfer the heat Though cooling iproves the voluetric efficiency, but over cooling result in the decrease of overall efficiency II. AIM OF THE PROJECT The ain ai of the project is to design and analyze cylinder with fins, by changing the thickness of the fins, and geoetry of the fin. Analyzation is also done by varying the aterials of fins. Present used aterial for cylinder fin body is uinu alloy 24 which has theral conductivity of w/k. Our ai is to change the aterial for fin body by analyzing the fin body with other aterials and also by changing the thickness. 214, IJIRAE- l Rights Reserved Page -286

2 Volue 1 Issue 8 (Septeber 214) Geoetry of fins Rectangular, Circular and Curve Shaped Thickness of fins 3 and 2.5 Materials uinu loy A24, uinu loy 775, Magnesiu alloy and u. STEPS INVOLVED IN THE PROJECT 1. MODELING 2. TRANSIENT THERMAL ANALYSIS For odeling of the fin body, we have used Pro-Engineer which is paraetric 3D odeling software. For analysis we have used ANSYS, which is FEA software III. MODELLING In this a cylinder fin body for hero 1cc otorcycle is odeled using paraetric software Pro/Engineer. The thickness of the original odel is 3, in this thesis it is reduced to 2.5. Original Fin Body Design B. Modification of Fin Body Fig. 1: 3 Thickness Fin Body fig 2: 2.5 thickness fin body IV. Experiental Procedure A. Analysis Transient theral analysis deterines teperatures and other theral quantities that vary over tie. The variation of teperature distribution over tie is of interest in any applications such as with cooling B. Build Geoetry Construct a two or three diensional representation of the object to be odeled and tested using the work plane co-ordinate syste within ANSYS. C. Define Material Properties Now that the part exists, define a library of the necessary aterials that copose the object (or project) being odeled. This includes theral and echanical properties.d. Generate Mesh At this point ANSYS understands the akeup of the part. Now define how the odeled syste should be broken down into finite pieces. E. Apply Loads Once the syste is fully designed, the last task is to burden the syste with constraints, such as physical loadings or boundary conditions. F. Obtain Solution This is actually a step, because ANSYS needs to understand within what state (steady state, transient etc.) the proble ust be solved. Figure. 214, IJIRAE- l Rights Reserved Page -287

3 Volue 1 Issue 8 (Septeber 214) In this, we have taken four types of etals having different properties. The tabular colun gives the values of theral conductivity, specific heat, density For these etals. LOADS APPLIED: The loads applied are Apply Theral-Teperature- on Area-Select inside area 585K Convections on Areas (select Reaining areas-fil Co-efficient 25 W/ K Bulk Teperature 313 K The given loads are applied on eshed odels of aluinu alloy 775, aluinu A24, Magnesiu, berylliu Now we calculated Nodal teperature, theral gradient, theral flux for all the etals taken of 2.5 and 3 thickness by using ansys software Here for convenience sake Properties Metals Theral Conductivity Specific Heat Density uinu loy A24 12 w/k.963 J/g ºC 2.8 g/cc uinu loy w/ k.96 J/g ºC 2.7 g/cc ALUMINUM ALLOY 24 : Magnesiu 159 w/ k 1.45 J/g ºC 2.48 g/cc u 216 w/ k.927 J/g ºC 1.87 g/cc we have shown only ansys odels of uinu alloy 24 of 3 and2.5 Thickness RECTANGULAR FIN 3 THICKNESS Nodal teperature Theral gradient Theral flux 3 THICKNESS ; Nodal Teperature Theral Gradient Theral Flux CURVED FIN: Nodal teperature Theral Gradient Theral Flux 214, IJIRAE- l Rights Reserved Page -288

4 Volue 1 Issue 8 (Septeber 214) IV RESULTS AND DISCUSSION FIN THICKNESS TYPE MATERIALS RESULTS NODAL TEMPERA TURE THERMAL GRADIENT HEAT FLUX Curved berylliu agnesiu Circular berylliu agnesiu Rectangular berylliu agnesiu Curved berylliu agnesiu Circular berylliu agnesiu Rectangular berylliu agnesiu GRAPHICAL REPRESENTATION: Thickness of 2.5 CURVED FIN: CIRCULAR FIN: RECTANGULAR FIN: Heat Flux Beryll iu Theral Magn Gradientesiu Heat Flux Theral Gradient 775 u Magn esiu Heat Flux Theral Gradient 775 u Magn esiu By observing the graphs, the heat flux is ore for u and uinu alloy 775. CURVED FIN: CIRCULAR FIN: 4 2 Heat Flux Theral Gradient u u 214, IJIRAE- l Rights Reserved Page -289

5 Volue 1 Issue 8 (Septeber 214) RECTANGULAR FIN: u By observing the graphs, the heat flux is ore for u and uinu alloy 775 Coparison of Thickness 2.5 and 3 CURVED: THERMAL GRADIENT THERMAL FLUX Magnesiu u 3. Magnesiu u By observing the graphs, the heat flux is ore for 2.5 CIRCULAR FIN: THERMAL GRADIENT THERMAL FLUX Magnesiu u Magnes iu u 775 RECTANGULAR FIN THERMAL GRADIENT THERMAL FLUX Magnesiu u Magnesiu u V. CONCLUSION In this Project, a cylinder fin body for a 18cc otorcycle is odeled using paraetric software Pro/Engineer. The original odel is changed by changing thickness of the fins. The thickness of original odel is 3, it has been reduced to 2.5. By reducing the thickness of the fins, the overall weight is reduced. 214, IJIRAE- l Rights Reserved Page -29

6 Volue 1 Issue 8 (Septeber 214) Present used aterial for fin body is uinu loy 24. In this thesis, three other aterials are considered which have ore theral conductivities than uinu loy 24. The aterials are uinu alloy 775, Magnesiu loy and u. Theral analysis is done for all the three aterials. The aterial for the original odel is changed by taking the consideration of their densities and theral conductivity. By observing the theral analysis results, theral flux is ore for u than other aterials and also by reducing the thickness of the fin 2.5, the heat transfer rate is increased. IV. FUTURE SCOPE The shape of the fin can be odified to iprove the heat transfer rate and can be analyzed. The use of uinu alloy 661 as per the anufacturing aspect is to be considered. By changing the thickness of the fin, the total anufacturing cost is extra to prepare the new coponent REFERENCES [1] Heat Transfer Siulation by CFD fro Fins of an Air Cooled Motorcycle Engine under Varying Cliatic Conditions by Pulkit Agarwal, Mayur Shrikhande and P. Srinivasan [2] The effect of fin spacing and aterial on the perforance of a heat sink with circular pin fins by A Dewan, P Patro, I Khan, and P Mahanta [3] Theral Engineering by Rudraoorthy [4] Theral Engineering by R.K. Rajput [5] Theral Engineering by Sarkar [6] Gibson, A.H., The Air Cooling of Petrol Engines, Proceedings of the Institute of Autoobile Engineers, Vol.XIV (192), pp Bierann, A.E. and Pinkel, B., Heat Transfer fro Finned Metal Cylinders in an Air Strea, NACA Report No.488 (1935). 214, IJIRAE- l Rights Reserved Page -291