International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 07 | July -2017
p-ISSN: 2395-0072
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EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER THROUGH RECTANGULAR AND TRAPEZOIDAL FINS MADE OF ALUMINUM 6063 ALLOY J. Koteswara rao 1, MD.Mansoor Ahamed2, S.Raju3 V.srikumar4 N.V SaiRam5 1,2,3,4Assistant
professor, Dept. of mechanical engineering, KKR & KSR INST. OF TECH. & SCIENCES, Guntur A.P, India. ---------------------------------------------------------------***---------------------------------------------------------------Abstract - In various applications, rectangular and trapezoidal finned surfaces are used to enhance the heat transfer in most of the equipment’s. In this paper an experimental attempt has been made to compare the performance of free and forced convective heat transfer form rectangular and trapezoidal fins attached to a heated horizontal base. For the experimentation fins are fabricated of dimensions 110*50*10mm for rectangular fin and length of 110x30x10 mm, (lengthXbaseX width) for trapezoidal fin by using aluminium 6063 alloy. The inherent thermal conductivity of alumi nium 6063 alloy is 200w/m-k which improves the efficiency of the rate of heat dissipation in rectangular and trapezoidal fins. Experiments have been carried out under steady state conditions. Local values of heat flux, temperature, heat transfer coefficien ts, Reynolds numbers have been estimated. experimental findings shows that forced convection is most effective than the free convection and Heat-transfer coefficient is enhanced for trapezoidal fin for the heat supply of 55W, 67W, 80W and 93W by 37%, 48%, 37%, and 22% at respective heat supply. Key Words: Free convection, Forced convection, extended surfaces, heat transfer coefficient, efficiency and effectiveness 1. INTRODUCTION Heat transfer by convection between a surface and the fluid surrounding can be increased by attaching to the surface thin metallic strips called Fins. The heat conducting through solids, walls or boundaries has to be continuously dissipated to the surrounding or environment to maintain the system in a steady state condition. In many engineering applications large quantities of heat need to be dissipated from small area. The fins increase the effective area of the surface there by increasing the heat transfer by convection. The fin is generally used when the convection heat transfer coefficient is low, especially under free convection. In the field of industry the fin is used widely, for instance, in cooling of electronic accessories, motorcycle engine and in air cooling of molecules with in a material 1.1 Types of fins The fins are also referred as ‘extended surfaces’. Fins are manufactured in different geometries, depending upon the practical applications. The ribs attached along the length of a tube are called longitudinal fins. The concentric macular discs around a tube are termed circumferential fins. Pin fins or spines are rods protruding from a surface. The fins may be of uniform or variable cross-section. They have many different practical applications, via cooling of electronic components, cooling of motor cycle engines, compressors, electric motors transformers, refrigerators, high-efficiency boiler super heater tubes etc. Solid gas turbines blades often act as fins, conducting heat down their length to a cool disc. Types of fins: 1) Triangular fin 2) Rectangular fin 3) Cylindrical fin
4) Trapezoidal fin 5)Parabolic fin 2. Literature review
Christopher L. Chapman et al [1994] Study of these papers comparative thermal tests has been carried out using aluminium heat sinks made with extruded fin, cross-cut rectangular pins, and elliptical shaped pins in low air flow environments. The elliptical pin heat sink was designed to minimize the pressure loss across the heat sink by reducing the vortex effects and to
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